Queryify has_attr to improve performance

Inspired by rust-lang#127144 (review)
and previous success in rust-lang#94897.

Author: camelid

compiler/rustc_middle/src/query/keys.rs

@@ -484,6 +484,14 @@ impl Key for Option<Symbol> {
     }
 }
 
+impl Key for (DefId, Symbol) {
+    type Cache<V> = DefaultCache<Self, V>;
+
+    fn default_span(&self, _tcx: TyCtxt<'_>) -> Span {
+        DUMMY_SP
+    }
+}
+
 /// Canonical query goals correspond to abstract trait operations that
 /// are not tied to any crate in particular.
 impl<'tcx, T: Clone> Key for Canonical<'tcx, T> {

compiler/rustc_middle/src/query/mod.rs

@@ -1226,6 +1226,12 @@ rustc_queries! {
         separate_provide_extern
     }
 
+    /// This query backs the [`TyCtxt::has_attr`] function to make it faster.
+    /// You should use that function instead.
+    query has_attr_query(key: (DefId, Symbol)) -> bool {
+        desc { |tcx| "checking whether `{}` has attr {}", tcx.def_path_str(key.0), key.1 }
+    }
+
     /// Determines whether an item is annotated with `doc(hidden)`.
     query is_doc_hidden(def_id: DefId) -> bool {
         desc { |tcx| "checking whether `{}` is `doc(hidden)`", tcx.def_path_str(def_id) }

compiler/rustc_middle/src/ty/mod.rs

@@ -1801,7 +1801,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Determines whether an item is annotated with an attribute.
     pub fn has_attr(self, did: impl Into<DefId>, attr: Symbol) -> bool {
-        self.get_attrs(did, attr).next().is_some()
+        self.has_attr_query((did.into(), attr))
     }
 
     /// Determines whether an item is annotated with a multi-segement attribute

compiler/rustc_middle/src/ty/util.rs

@@ -19,7 +19,7 @@ use rustc_hir::def_id::{CrateNum, DefId, LocalDefId};
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_macros::{extension, HashStable, TyDecodable, TyEncodable};
 use rustc_session::Limit;
-use rustc_span::sym;
+use rustc_span::{sym, Symbol};
 use rustc_target::abi::{Float, Integer, IntegerType, Size};
 use rustc_target::spec::abi::Abi;
 use smallvec::{smallvec, SmallVec};
@@ -1829,6 +1829,12 @@ pub fn reveal_opaque_types_in_bounds<'tcx>(
     val.fold_with(&mut visitor)
 }
 
+/// Determines whether an item is annotated with an attribute.
+pub fn has_attr_query(tcx: TyCtxt<'_>, key: (DefId, Symbol)) -> bool {
+    let (did, attr) = key;
+    tcx.get_attrs(did, attr).next().is_some()
+}
+
 /// Determines whether an item is directly annotated with `doc(hidden)`.
 fn is_doc_hidden(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
     tcx.get_attrs(def_id, sym::doc)
@@ -1865,6 +1871,7 @@ pub fn intrinsic_raw(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::Intrinsi
 pub fn provide(providers: &mut Providers) {
     *providers = Providers {
         reveal_opaque_types_in_bounds,
+        has_attr_query,
         is_doc_hidden,
         is_doc_notable_trait,
         intrinsic_raw,