Parse #[rustc_evaluate_where_clauses]

Author: Ozzy1423

compiler/rustc_attr_parsing/src/attributes/test_attrs.rs

@@ -149,3 +149,18 @@ impl<S: Stage> NoArgsAttributeParser<S> for RustcDelayedBugFromInsideQueryParser
     const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Fn)]);
     const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcDelayedBugFromInsideQuery;
 }
+
+pub(crate) struct RustcEvaluateWhereClausesParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcEvaluateWhereClausesParser {
+    const PATH: &[Symbol] = &[sym::rustc_evaluate_where_clauses];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Fn),
+        Allow(Target::Method(MethodKind::Inherent)),
+        Allow(Target::Method(MethodKind::Trait { body: true })),
+        Allow(Target::Method(MethodKind::TraitImpl)),
+        Allow(Target::Method(MethodKind::Trait { body: false })),
+    ]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcEvaluateWhereClauses;
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -259,6 +259,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcDumpPredicatesParser>>,
         Single<WithoutArgs<RustcDumpUserArgsParser>>,
         Single<WithoutArgs<RustcDumpVtableParser>>,
+        Single<WithoutArgs<RustcEvaluateWhereClausesParser>>,
         Single<WithoutArgs<RustcHasIncoherentInherentImplsParser>>,
         Single<WithoutArgs<RustcHiddenTypeOfOpaquesParser>>,
         Single<WithoutArgs<RustcLintOptTyParser>>,

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -1097,6 +1097,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_dyn_incompatible_trait]`.
     RustcDynIncompatibleTrait(Span),
 
+    /// Represents `#[rustc_evaluate_where_clauses]`
+    RustcEvaluateWhereClauses,
+
     /// Represents `#[rustc_has_incoherent_inherent_impls]`
     RustcHasIncoherentInherentImpls,
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -113,6 +113,7 @@ impl AttributeKind {
             RustcDumpUserArgs => No,
             RustcDumpVtable(..) => No,
             RustcDynIncompatibleTrait(..) => No,
+            RustcEvaluateWhereClauses => Yes,
             RustcHasIncoherentInherentImpls => Yes,
             RustcHiddenTypeOfOpaques => No,
             RustcIfThisChanged(..) => No,

compiler/rustc_hir_typeck/src/callee.rs

@@ -3,9 +3,10 @@ use std::iter;
 use rustc_abi::{CanonAbi, ExternAbi};
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_errors::{Applicability, Diag, ErrorGuaranteed, StashKey, inline_fluent};
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::{self, CtorKind, Namespace, Res};
 use rustc_hir::def_id::DefId;
-use rustc_hir::{self as hir, HirId, LangItem};
+use rustc_hir::{self as hir, HirId, LangItem, find_attr};
 use rustc_hir_analysis::autoderef::Autoderef;
 use rustc_infer::infer::BoundRegionConversionTime;
 use rustc_infer::traits::{Obligation, ObligationCause, ObligationCauseCode};
@@ -526,7 +527,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // `#[rustc_evaluate_where_clauses]` trigger special output
                 // to let us test the trait evaluation system.
                 if self.has_rustc_attrs
-                    && self.tcx.has_attr(def_id, sym::rustc_evaluate_where_clauses)
+                    && find_attr!(
+                        self.tcx.get_all_attrs(def_id),
+                        AttributeKind::RustcEvaluateWhereClauses
+                    )
                 {
                     let predicates = self.tcx.predicates_of(def_id);
                     let predicates = predicates.instantiate(self.tcx, args);

compiler/rustc_passes/src/check_attr.rs

@@ -308,6 +308,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcDumpUserArgs
                     | AttributeKind::RustcDumpVtable(..)
                     | AttributeKind::RustcDynIncompatibleTrait(..)
+                    | AttributeKind::RustcEvaluateWhereClauses
                     | AttributeKind::RustcHasIncoherentInherentImpls
                     | AttributeKind::RustcHiddenTypeOfOpaques
                     | AttributeKind::RustcIfThisChanged(..)
@@ -405,7 +406,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::rustc_effective_visibility
                             | sym::rustc_outlives
                             | sym::rustc_symbol_name
-                            | sym::rustc_evaluate_where_clauses
                             | sym::rustc_def_path
                             | sym::rustc_partition_reused
                             | sym::rustc_partition_codegened