From 7356ff7517f4d95583f8fd6d631441893c87dd3f Mon Sep 17 00:00:00 2001 From: tiif Date: Mon, 14 Jul 2025 13:38:19 +0000 Subject: [PATCH] Implement other logics --- .../src/encode_cross_crate.rs | 1 + compiler/rustc_attr_parsing/src/context.rs | 5 ++- compiler/rustc_feature/src/builtin_attrs.rs | 4 ++ .../rustc_hir_analysis/src/check/wfcheck.rs | 14 ++++--- .../src/collect/predicates_of.rs | 2 + .../src/impl_wf_check/min_specialization.rs | 1 + .../src/outlives/explicit.rs | 1 + .../src/fn_ctxt/inspect_obligations.rs | 1 + compiler/rustc_hir_typeck/src/method/probe.rs | 1 + compiler/rustc_lint/src/builtin.rs | 3 +- compiler/rustc_middle/src/ty/context.rs | 1 + compiler/rustc_middle/src/ty/predicate.rs | 3 ++ compiler/rustc_middle/src/ty/print/pretty.rs | 1 + compiler/rustc_privacy/src/lib.rs | 1 + .../src/unstable/convert/stable/ty.rs | 3 ++ compiler/rustc_session/src/parse.rs | 40 +++++++++++++++++++ compiler/rustc_span/src/symbol.rs | 1 + .../src/error_reporting/traits/ambiguity.rs | 25 ++++++++++++ .../traits/fulfillment_errors.rs | 2 + .../src/traits/auto_trait.rs | 1 + .../src/traits/dyn_compatibility.rs | 2 + .../src/traits/fulfill.rs | 3 ++ .../query/type_op/implied_outlives_bounds.rs | 1 + .../rustc_trait_selection/src/traits/util.rs | 1 + .../rustc_trait_selection/src/traits/wf.rs | 2 + .../src/normalize_erasing_regions.rs | 1 + compiler/rustc_type_ir/src/elaborate.rs | 3 ++ compiler/rustc_type_ir/src/flags.rs | 3 +- compiler/rustc_type_ir/src/interner.rs | 1 + compiler/rustc_type_ir/src/predicate_kind.rs | 10 +++++ src/librustdoc/clean/mod.rs | 3 +- 31 files changed, 132 insertions(+), 9 deletions(-) diff --git a/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs b/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs index 494b570c86c7..84c3bd1eb614 100644 --- a/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs +++ b/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs @@ -70,6 +70,7 @@ impl AttributeKind { TrackCaller(..) => Yes, TypeConst(..) => Yes, UnsafeSpecializationMarker(..) => No, + UnstableFeatureBound(..) => No, Used { .. } => No, // tidy-alphabetical-end } diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs index 1f6675b4c5a8..390246239ed1 100644 --- a/compiler/rustc_attr_parsing/src/context.rs +++ b/compiler/rustc_attr_parsing/src/context.rs @@ -13,7 +13,9 @@ use rustc_hir::{AttrArgs, AttrItem, AttrPath, Attribute, HashIgnoredAttrId, HirI use rustc_session::Session; use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym}; -use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser}; +use crate::attributes::allow_unstable::{ + AllowConstFnUnstableParser, AllowInternalUnstableParser, UnstableFeatureBoundParser, +}; use crate::attributes::codegen_attrs::{ ColdParser, ExportNameParser, NakedParser, NoMangleParser, OmitGdbPrettyPrinterSectionParser, OptimizeParser, TargetFeatureParser, TrackCallerParser, UsedParser, @@ -133,6 +135,7 @@ attribute_parsers!( Combine, Combine, Combine, + Combine, // tidy-alphabetical-end // tidy-alphabetical-start diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs index 7d9915d7f68b..e2827f227abf 100644 --- a/compiler/rustc_feature/src/builtin_attrs.rs +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -683,6 +683,10 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[ template!(List: r#"feature = "name", reason = "...", issue = "N""#), DuplicatesOk, EncodeCrossCrate::Yes ), + ungated!( + unstable_feature_bound, Normal, template!(Word, List: "feat1, feat2, ..."), + DuplicatesOk, EncodeCrossCrate::No, + ), ungated!( rustc_const_unstable, Normal, template!(List: r#"feature = "name""#), DuplicatesOk, EncodeCrossCrate::Yes diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index 607028f4d9ae..14ec82ede1c5 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -2212,12 +2212,16 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> { let implied_obligations = traits::elaborate(tcx, predicates_with_span); for (pred, obligation_span) in implied_obligations { - // We lower empty bounds like `Vec:` as - // `WellFormed(Vec)`, which will later get checked by - // regular WF checking - if let ty::ClauseKind::WellFormed(..) = pred.kind().skip_binder() { - continue; + match pred.kind().skip_binder() { + // We lower empty bounds like `Vec:` as + // `WellFormed(Vec)`, which will later get checked by + // regular WF checking + ty::ClauseKind::WellFormed(..) + // Unstable feature goals cannot be proven in an empty environment so skip them + | ty::ClauseKind::UnstableFeature(..) => continue, + _ => {} } + // Match the existing behavior. if pred.is_global() && !pred.has_type_flags(TypeFlags::HAS_BINDER_VARS) { let pred = self.normalize(span, None, pred); diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs index 60ccc484e002..af78130899e4 100644 --- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs @@ -778,6 +778,7 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>( ty::ClauseKind::RegionOutlives(_) | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::ConstEvaluatable(_) => { bug!( "unexpected non-`Self` predicate when computing \ @@ -805,6 +806,7 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>( | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => { bug!( "unexpected non-`Self` predicate when computing \ diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs index 574d19a5aa5a..0043f0c71176 100644 --- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs +++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs @@ -499,6 +499,7 @@ fn trait_specialization_kind<'tcx>( | ty::ClauseKind::ConstArgHasType(..) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(..) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => None, } } diff --git a/compiler/rustc_hir_analysis/src/outlives/explicit.rs b/compiler/rustc_hir_analysis/src/outlives/explicit.rs index 2c1d443f9512..d3a57a4d8e5d 100644 --- a/compiler/rustc_hir_analysis/src/outlives/explicit.rs +++ b/compiler/rustc_hir_analysis/src/outlives/explicit.rs @@ -54,6 +54,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> { | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => {} } } diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs index e4c62bf027bd..367e2b6b372a 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs @@ -54,6 +54,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { | ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..)) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..)) + | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) | ty::PredicateKind::Ambiguous => false, } } diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs index 94c93e736274..3261327a9fda 100644 --- a/compiler/rustc_hir_typeck/src/method/probe.rs +++ b/compiler/rustc_hir_typeck/src/method/probe.rs @@ -921,6 +921,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> { | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => None, } }); diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 255ff56f62b1..8244f0bed4c9 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -1519,8 +1519,9 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { ClauseKind::TypeOutlives(..) | ClauseKind::RegionOutlives(..) => "lifetime", + ClauseKind::UnstableFeature(_) // `ConstArgHasType` is never global as `ct` is always a param - ClauseKind::ConstArgHasType(..) + | ClauseKind::ConstArgHasType(..) // Ignore projections, as they can only be global // if the trait bound is global | ClauseKind::Projection(..) diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 290213cab5e6..915b062417f2 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -137,6 +137,7 @@ impl<'tcx> Interner for TyCtxt<'tcx> { type FnInputTys = &'tcx [Ty<'tcx>]; type ParamTy = ParamTy; type BoundTy = ty::BoundTy; + type Symbol = Symbol; type PlaceholderTy = ty::PlaceholderType; type ErrorGuaranteed = ErrorGuaranteed; diff --git a/compiler/rustc_middle/src/ty/predicate.rs b/compiler/rustc_middle/src/ty/predicate.rs index bc2ac42b6b1f..ec2224877a8a 100644 --- a/compiler/rustc_middle/src/ty/predicate.rs +++ b/compiler/rustc_middle/src/ty/predicate.rs @@ -131,6 +131,7 @@ impl<'tcx> Predicate<'tcx> { | PredicateKind::Clause(ClauseKind::TypeOutlives(_)) | PredicateKind::Clause(ClauseKind::Projection(_)) | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) + | PredicateKind::Clause(ClauseKind::UnstableFeature(_)) | PredicateKind::DynCompatible(_) | PredicateKind::Subtype(_) | PredicateKind::Coerce(_) @@ -649,6 +650,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(ClauseKind::Projection(..)) | PredicateKind::Clause(ClauseKind::HostEffect(..)) | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) + | PredicateKind::Clause(ClauseKind::UnstableFeature(_)) | PredicateKind::NormalizesTo(..) | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) @@ -670,6 +672,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(ClauseKind::Trait(..)) | PredicateKind::Clause(ClauseKind::HostEffect(..)) | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) + | PredicateKind::Clause(ClauseKind::UnstableFeature(_)) | PredicateKind::NormalizesTo(..) | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index 7c48a4b0885e..b857788b8b7e 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -3237,6 +3237,7 @@ define_print! { ty::ClauseKind::ConstEvaluatable(ct) => { p!("the constant `", print(ct), "` can be evaluated") } + ty::ClauseKind::UnstableFeature(symbol) => p!("unstable feature: ", write("`{}`", symbol)), } } diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs index ab2433234aa9..80c13e44d7d8 100644 --- a/compiler/rustc_privacy/src/lib.rs +++ b/compiler/rustc_privacy/src/lib.rs @@ -156,6 +156,7 @@ where } ty::ClauseKind::ConstEvaluatable(ct) => ct.visit_with(self), ty::ClauseKind::WellFormed(term) => term.visit_with(self), + ty::ClauseKind::UnstableFeature(_) => V::Result::output(), } } diff --git a/compiler/rustc_public/src/unstable/convert/stable/ty.rs b/compiler/rustc_public/src/unstable/convert/stable/ty.rs index 75c297887875..6b226b8a24d1 100644 --- a/compiler/rustc_public/src/unstable/convert/stable/ty.rs +++ b/compiler/rustc_public/src/unstable/convert/stable/ty.rs @@ -764,6 +764,9 @@ impl<'tcx> Stable<'tcx> for ty::ClauseKind<'tcx> { ClauseKind::HostEffect(..) => { todo!() } + ClauseKind::UnstableFeature(_) => { + todo!() + } } } } diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs index 0118cdb1fc27..ea7a524efe6d 100644 --- a/compiler/rustc_session/src/parse.rs +++ b/compiler/rustc_session/src/parse.rs @@ -205,6 +205,46 @@ pub fn add_feature_diagnostics_for_issue( } } +/// This is only used by unstable_feature_bound as it does not have issue number information for now. +/// This is basically the same as `feature_err_issue` +/// but without the feature issue note. If we can do a lookup for issue number from feature name, +/// then we should directly use `feature_err_issue` for ambiguity error of +/// #[unstable_feature_bound]. +#[track_caller] +pub fn feature_err_unstable_feature_bound( + sess: &Session, + feature: Symbol, + span: impl Into, + explain: impl Into, +) -> Diag<'_> { + let span = span.into(); + + // Cancel an earlier warning for this same error, if it exists. + if let Some(span) = span.primary_span() { + if let Some(err) = sess.dcx().steal_non_err(span, StashKey::EarlySyntaxWarning) { + err.cancel() + } + } + + let mut err = sess.dcx().create_err(FeatureGateError { span, explain: explain.into() }); + + // #23973: do not suggest `#![feature(...)]` if we are in beta/stable + if sess.psess.unstable_features.is_nightly_build() { + err.subdiagnostic(FeatureDiagnosticHelp { feature }); + + if feature == sym::rustc_attrs { + // We're unlikely to stabilize something out of `rustc_attrs` + // without at least renaming it, so pointing out how old + // the compiler is will do little good. + } else if sess.opts.unstable_opts.ui_testing { + err.subdiagnostic(SuggestUpgradeCompiler::ui_testing()); + } else if let Some(suggestion) = SuggestUpgradeCompiler::new() { + err.subdiagnostic(suggestion); + } + } + err +} + /// Info about a parsing session. pub struct ParseSess { dcx: DiagCtxt, diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 8b12edf426c1..bd34055f8513 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -2284,6 +2284,7 @@ symbols! { unsized_locals, unsized_tuple_coercion, unstable, + unstable_feature_bound, unstable_location_reason_default: "this crate is being loaded from the sysroot, an \ unstable location; did you mean to load this crate \ from crates.io via `Cargo.toml` instead?", diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs index 712e88300fff..98f67257fd13 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs @@ -12,6 +12,7 @@ use rustc_infer::traits::{ Obligation, ObligationCause, ObligationCauseCode, PolyTraitObligation, PredicateObligation, }; use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable as _, TypeVisitableExt as _}; +use rustc_session::parse::feature_err_unstable_feature_bound; use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span}; use tracing::{debug, instrument}; @@ -611,6 +612,30 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { ) .with_span_label(span, format!("cannot normalize `{alias}`")) } + ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(sym)) => { + if let Some(e) = self.tainted_by_errors() { + return e; + } + + let mut err; + + if self.tcx.features().staged_api() { + err = self.dcx().struct_span_err( + span, + format!("unstable feature `{sym}` is used without being enabled."), + ); + + err.help(format!("The feature can be enabled by marking the current item with `#[unstable_feature_bound({sym})]`")); + } else { + err = feature_err_unstable_feature_bound( + &self.tcx.sess, + sym, + span, + format!("use of unstable library feature `{sym}`"), + ); + } + err + } _ => { if let Some(e) = self.tainted_by_errors() { diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index cd3e6c4bc543..1ac309da101f 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -647,6 +647,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { | ty::PredicateKind::ConstEquate { .. } // Ambiguous predicates should never error | ty::PredicateKind::Ambiguous + // We never return Err when proving UnstableFeature goal. + | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature{ .. }) | ty::PredicateKind::NormalizesTo { .. } | ty::PredicateKind::AliasRelate { .. } | ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType { .. }) => { diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 3ae908ec16b8..759db1d18c01 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -800,6 +800,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { // FIXME(generic_const_exprs): you can absolutely add this as a where clauses | ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..)) | ty::PredicateKind::Coerce(..) + | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..)) => {} ty::PredicateKind::Ambiguous => return false, }; diff --git a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs index 9a4f3887bbb5..ea1eed957233 100644 --- a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs +++ b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs @@ -238,6 +238,7 @@ fn predicate_references_self<'tcx>( // FIXME(generic_const_exprs): this can mention `Self` | ty::ClauseKind::ConstEvaluatable(..) | ty::ClauseKind::HostEffect(..) + | ty::ClauseKind::UnstableFeature(_) => None, } } @@ -278,6 +279,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool { | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => false, }) } diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index 3e13e5042667..2b5a41ef5a71 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -406,6 +406,9 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> { ty::PredicateKind::AliasRelate(..) => { bug!("AliasRelate is only used by the new solver") } + ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) => { + unreachable!("unexpected higher ranked `UnstableFeature` goal") + } }, Some(pred) => match pred { ty::PredicateKind::Clause(ty::ClauseKind::Trait(data)) => { diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs index e294f7839aac..7540cbe3fd1a 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs @@ -110,6 +110,7 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>( | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous | ty::PredicateKind::NormalizesTo(..) + | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) | ty::PredicateKind::AliasRelate(..) => {} // We need to search through *all* WellFormed predicates diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs index 141454bfe375..25cd7787a349 100644 --- a/compiler/rustc_trait_selection/src/traits/util.rs +++ b/compiler/rustc_trait_selection/src/traits/util.rs @@ -80,6 +80,7 @@ pub fn expand_trait_aliases<'tcx>( | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) | ty::ClauseKind::ConstEvaluatable(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::HostEffect(..) => {} } } diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index fed9f254cdf8..adce9850b594 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -197,6 +197,7 @@ pub fn clause_obligations<'tcx>( ty::ClauseKind::ConstEvaluatable(ct) => { wf.add_wf_preds_for_term(ct.into()); } + ty::ClauseKind::UnstableFeature(_) => {} } wf.normalize(infcx) @@ -1095,6 +1096,7 @@ pub fn object_region_bounds<'tcx>( | ty::ClauseKind::Projection(_) | ty::ClauseKind::ConstArgHasType(_, _) | ty::ClauseKind::WellFormed(_) + | ty::ClauseKind::UnstableFeature(_) | ty::ClauseKind::ConstEvaluatable(_) => None, } }) diff --git a/compiler/rustc_traits/src/normalize_erasing_regions.rs b/compiler/rustc_traits/src/normalize_erasing_regions.rs index 68ff66bbce7c..c1b848a2e79d 100644 --- a/compiler/rustc_traits/src/normalize_erasing_regions.rs +++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs @@ -57,6 +57,7 @@ fn not_outlives_predicate(p: ty::Predicate<'_>) -> bool { | ty::PredicateKind::Clause(ty::ClauseKind::Projection(..)) | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..)) | ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(..)) + | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) | ty::PredicateKind::NormalizesTo(..) | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(..)) diff --git a/compiler/rustc_type_ir/src/elaborate.rs b/compiler/rustc_type_ir/src/elaborate.rs index 7ffcf7b5d965..380082487579 100644 --- a/compiler/rustc_type_ir/src/elaborate.rs +++ b/compiler/rustc_type_ir/src/elaborate.rs @@ -234,6 +234,9 @@ impl> Elaborator { ty::ClauseKind::ConstArgHasType(..) => { // Nothing to elaborate } + ty::ClauseKind::UnstableFeature(_) => { + // Nothing to elaborate + } } } } diff --git a/compiler/rustc_type_ir/src/flags.rs b/compiler/rustc_type_ir/src/flags.rs index 37cc2baa402a..a231908f874c 100644 --- a/compiler/rustc_type_ir/src/flags.rs +++ b/compiler/rustc_type_ir/src/flags.rs @@ -401,7 +401,6 @@ impl FlagComputation { self.add_const(expected); self.add_const(found); } - ty::PredicateKind::Ambiguous => {} ty::PredicateKind::NormalizesTo(ty::NormalizesTo { alias, term }) => { self.add_alias_term(alias); self.add_term(term); @@ -410,6 +409,8 @@ impl FlagComputation { self.add_term(t1); self.add_term(t2); } + ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_sym)) => {} + ty::PredicateKind::Ambiguous => {} } } diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs index dd3cf1fc1811..0ec326d21169 100644 --- a/compiler/rustc_type_ir/src/interner.rs +++ b/compiler/rustc_type_ir/src/interner.rs @@ -106,6 +106,7 @@ pub trait Interner: type ParamTy: ParamLike; type BoundTy: BoundVarLike; type PlaceholderTy: PlaceholderLike; + type Symbol: Copy + Hash + PartialEq + Eq + Debug; // Things stored inside of tys type ErrorGuaranteed: Copy + Debug + Hash + Eq; diff --git a/compiler/rustc_type_ir/src/predicate_kind.rs b/compiler/rustc_type_ir/src/predicate_kind.rs index 4e41fd16ffd7..8bc15ec4ff55 100644 --- a/compiler/rustc_type_ir/src/predicate_kind.rs +++ b/compiler/rustc_type_ir/src/predicate_kind.rs @@ -46,6 +46,13 @@ pub enum ClauseKind { /// corresponding trait clause; this just enforces the *constness* of that /// implementation. HostEffect(ty::HostEffectPredicate), + + /// Support marking impl as unstable. + UnstableFeature( + #[type_foldable(identity)] + #[type_visitable(ignore)] + I::Symbol, + ), } #[derive_where(Clone, Copy, Hash, PartialEq, Eq; I: Interner)] @@ -134,6 +141,9 @@ impl fmt::Debug for ClauseKind { ClauseKind::ConstEvaluatable(ct) => { write!(f, "ConstEvaluatable({ct:?})") } + ClauseKind::UnstableFeature(feature_name) => { + write!(f, "UnstableFeature({feature_name:?})") + } } } } diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index e7a1f4d8397b..3df04091f163 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -390,7 +390,8 @@ pub(crate) fn clean_predicate<'tcx>( ty::ClauseKind::ConstEvaluatable(..) | ty::ClauseKind::WellFormed(..) | ty::ClauseKind::ConstArgHasType(..) - // FIXME(const_trait_impl): We can probably use this `HostEffect` pred to render `[const]`. + | ty::ClauseKind::UnstableFeature(..) + // FIXME(const_trait_impl): We can probably use this `HostEffect` pred to render `~const`. | ty::ClauseKind::HostEffect(_) => None, } }