Auto merge of #117005 - cuviper:beta-next, r=cuviper

[beta] backports and stage0 bump

- Bump stage0 to released stable compiler
- Hide host effect params from docs #116670
- Fix a performance regression in obligation deduplication. #116826
- Make `#[repr(Rust)]` and `#[repr(C)]` incompatible with one another #116829
- Update to LLVM 17.0.3 #116840
- Disable effects in libcore again #116856
- revert rust-lang/rust#114586 #116879

r? cuviper

7 files changed, 40 insertions, 89 deletions

diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index b7da15af6dc..4da7b602571 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -328,26 +328,19 @@ fn check_opaque_type_well_formed<'tcx>(
 
     // Require that the hidden type actually fulfills all the bounds of the opaque type, even without
     // the bounds that the function supplies.
-    let mut obligations = vec![];
-    infcx
-        .insert_hidden_type(
-            OpaqueTypeKey { def_id, args: identity_args },
-            &ObligationCause::misc(definition_span, def_id),
-            param_env,
-            definition_ty,
-            true,
-            &mut obligations,
-        )
-        .unwrap();
-    infcx.add_item_bounds_for_hidden_type(
-        def_id.to_def_id(),
-        identity_args,
-        ObligationCause::misc(definition_span, def_id),
-        param_env,
-        definition_ty,
-        &mut obligations,
-    );
-    ocx.register_obligations(obligations);
+    let opaque_ty = Ty::new_opaque(tcx, def_id.to_def_id(), identity_args);
+    ocx.eq(&ObligationCause::misc(definition_span, def_id), param_env, opaque_ty, definition_ty)
+        .map_err(|err| {
+            infcx
+                .err_ctxt()
+                .report_mismatched_types(
+                    &ObligationCause::misc(definition_span, def_id),
+                    opaque_ty,
+                    definition_ty,
+                    err,
+                )
+                .emit()
+        })?;
 
     // Require the hidden type to be well-formed with only the generics of the opaque type.
     // Defining use functions may have more bounds than the opaque type, which is ok, as long as the
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index 09df93fcc2f..1c3a5c36076 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -145,25 +145,7 @@ impl<'tcx> InferCtxt<'tcx> {
                             return None;
                         }
                     }
-                    DefiningAnchor::Bubble => {
-                        if let ty::Alias(ty::Opaque, _) = b.kind() {
-                            // In bubble mode we don't know which of the two opaque types is supposed to have the other
-                            // as a hidden type (both, none or either one of them could be in its defining scope).
-                            let predicate = ty::PredicateKind::AliasRelate(
-                                a.into(),
-                                b.into(),
-                                ty::AliasRelationDirection::Equate,
-                            );
-                            let obligation = traits::Obligation::new(
-                                self.tcx,
-                                cause.clone(),
-                                param_env,
-                                predicate,
-                            );
-                            let obligations = vec![obligation];
-                            return Some(Ok(InferOk { value: (), obligations }));
-                        }
-                    }
+                    DefiningAnchor::Bubble => {}
                     DefiningAnchor::Error => return None,
                 };
                 if let ty::Alias(ty::Opaque, ty::AliasTy { def_id: b_def_id, .. }) = *b.kind() {
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 9a7564cb213..d92923e78ff 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -1767,6 +1767,7 @@ impl CheckAttrVisitor<'_> {
             .collect();
 
         let mut int_reprs = 0;
+        let mut is_explicit_rust = false;
         let mut is_c = false;
         let mut is_simd = false;
         let mut is_transparent = false;
@@ -1778,7 +1779,9 @@ impl CheckAttrVisitor<'_> {
             }
 
             match hint.name_or_empty() {
-                sym::Rust => {}
+                sym::Rust => {
+                    is_explicit_rust = true;
+                }
                 sym::C => {
                     is_c = true;
                     match target {
@@ -1888,12 +1891,16 @@ impl CheckAttrVisitor<'_> {
 
         // Error on repr(transparent, <anything else>).
         if is_transparent && hints.len() > 1 {
-            let hint_spans: Vec<_> = hint_spans.clone().collect();
+            let hint_spans = hint_spans.clone().collect();
             self.tcx.sess.emit_err(errors::TransparentIncompatible {
                 hint_spans,
                 target: target.to_string(),
             });
         }
+        if is_explicit_rust && (int_reprs > 0 || is_c || is_simd) {
+            let hint_spans = hint_spans.clone().collect();
+            self.tcx.sess.emit_err(errors::ReprConflicting { hint_spans });
+        }
         // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8)
         if (int_reprs > 1)
             || (is_simd && is_c)
@@ -1910,7 +1917,7 @@ impl CheckAttrVisitor<'_> {
                 CONFLICTING_REPR_HINTS,
                 hir_id,
                 hint_spans.collect::<Vec<Span>>(),
-                errors::ReprConflicting,
+                errors::ReprConflictingLint,
             );
         }
     }
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index bcf5abbfe7d..f4a6bf017d6 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -558,9 +558,16 @@ pub struct ReprIdent {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(passes_repr_conflicting, code = "E0566")]
+pub struct ReprConflicting {
+    #[primary_span]
+    pub hint_spans: Vec<Span>,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(passes_repr_conflicting, code = "E0566")]
-pub struct ReprConflicting;
+pub struct ReprConflictingLint;
 
 #[derive(Diagnostic)]
 #[diag(passes_used_static)]
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index da357dac415..55b5604b16b 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -6,7 +6,6 @@ use rustc_infer::infer::DefineOpaqueTypes;
 use rustc_infer::traits::ProjectionCacheKey;
 use rustc_infer::traits::{PolyTraitObligation, SelectionError, TraitEngine};
 use rustc_middle::mir::interpret::ErrorHandled;
-use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::GenericArgsRef;
@@ -626,27 +625,9 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                     }
                 }
                 ty::PredicateKind::Ambiguous => ProcessResult::Unchanged,
-                ty::PredicateKind::AliasRelate(..)
-                    if matches!(self.selcx.infcx.defining_use_anchor, DefiningAnchor::Bubble) =>
-                {
-                    ProcessResult::Unchanged
+                ty::PredicateKind::AliasRelate(..) => {
+                    bug!("AliasRelate is only used for new solver")
                 }
-                ty::PredicateKind::AliasRelate(a, b, relate) => match relate {
-                    ty::AliasRelationDirection::Equate => match self
-                        .selcx
-                        .infcx
-                        .at(&obligation.cause, obligation.param_env)
-                        .eq(DefineOpaqueTypes::Yes, a, b)
-                    {
-                        Ok(inf_ok) => ProcessResult::Changed(mk_pending(inf_ok.into_obligations())),
-                        Err(_) => ProcessResult::Error(FulfillmentErrorCode::CodeSelectionError(
-                            SelectionError::Unimplemented,
-                        )),
-                    },
-                    ty::AliasRelationDirection::Subtype => {
-                        bug!("AliasRelate with subtyping is only used for new solver")
-                    }
-                },
                 ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
                     match self.selcx.infcx.at(&obligation.cause, obligation.param_env).eq(
                         DefineOpaqueTypes::No,
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 154cc7a7141..f7b4794dbab 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1233,7 +1233,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
 
             let projected_term = selcx.infcx.resolve_vars_if_possible(projected_term);
 
-            let result = if projected_term.has_projections() {
+            let mut result = if projected_term.has_projections() {
                 let mut normalizer = AssocTypeNormalizer::new(
                     selcx,
                     param_env,
@@ -1243,14 +1243,14 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
                 );
                 let normalized_ty = normalizer.fold(projected_term);
 
-                let mut deduped = SsoHashSet::with_capacity(projected_obligations.len());
-                projected_obligations.retain(|obligation| deduped.insert(obligation.clone()));
-
                 Normalized { value: normalized_ty, obligations: projected_obligations }
             } else {
                 Normalized { value: projected_term, obligations: projected_obligations }
             };
 
+            let mut deduped = SsoHashSet::with_capacity(result.obligations.len());
+            result.obligations.retain(|obligation| deduped.insert(obligation.clone()));
+
             if use_cache {
                 infcx.inner.borrow_mut().projection_cache().insert_term(cache_key, result.clone());
             }
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index bc9ba85fc9f..ec46a676983 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -38,7 +38,6 @@ use rustc_infer::traits::TraitObligation;
 use rustc_middle::dep_graph::dep_kinds;
 use rustc_middle::dep_graph::DepNodeIndex;
 use rustc_middle::mir::interpret::ErrorHandled;
-use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::relate::TypeRelation;
@@ -1003,27 +1002,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         }
                     }
                 }
-                ty::PredicateKind::AliasRelate(..)
-                    if matches!(self.infcx.defining_use_anchor, DefiningAnchor::Bubble) =>
-                {
-                    Ok(EvaluatedToAmbig)
+                ty::PredicateKind::AliasRelate(..) => {
+                    bug!("AliasRelate is only used for new solver")
                 }
-                ty::PredicateKind::AliasRelate(a, b, relate) => match relate {
-                    ty::AliasRelationDirection::Equate => match self
-                        .infcx
-                        .at(&obligation.cause, obligation.param_env)
-                        .eq(DefineOpaqueTypes::Yes, a, b)
-                    {
-                        Ok(inf_ok) => self.evaluate_predicates_recursively(
-                            previous_stack,
-                            inf_ok.into_obligations(),
-                        ),
-                        Err(_) => Ok(EvaluatedToErr),
-                    },
-                    ty::AliasRelationDirection::Subtype => {
-                        bug!("AliasRelate subtyping is only used for new solver")
-                    }
-                },
                 ty::PredicateKind::Ambiguous => Ok(EvaluatedToAmbig),
                 ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
                     match self.infcx.at(&obligation.cause, obligation.param_env).eq(