Use () for HIR queries.

compiler/rustc_middle/src/hir/map/mod.rs

@@ -150,7 +150,7 @@ impl<'hir> Iterator for ParentOwnerIterator<'_, 'hir> {
 
 impl<'hir> Map<'hir> {
     pub fn krate(&self) -> &'hir Crate<'hir> {
-        self.tcx.hir_crate(LOCAL_CRATE)
+        self.tcx.hir_crate(())
     }
 
     #[inline]
@@ -489,7 +489,7 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn trait_impls(&self, trait_did: DefId) -> &'hir [LocalDefId] {
-        self.tcx.all_local_trait_impls(LOCAL_CRATE).get(&trait_did).map_or(&[], |xs| &xs[..])
+        self.tcx.all_local_trait_impls(()).get(&trait_did).map_or(&[], |xs| &xs[..])
     }
 
     /// Gets the attributes on the crate. This is preferable to
@@ -928,9 +928,7 @@ impl<'hir> intravisit::Map<'hir> for Map<'hir> {
     }
 }
 
-pub(super) fn index_hir<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> &'tcx IndexedHir<'tcx> {
-    assert_eq!(cnum, LOCAL_CRATE);
-
+pub(super) fn index_hir<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> &'tcx IndexedHir<'tcx> {
     let _prof_timer = tcx.sess.prof.generic_activity("build_hir_map");
 
     let hcx = tcx.create_stable_hashing_context();
@@ -943,10 +941,12 @@ pub(super) fn index_hir<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> &'tcx Indexe
 }
 
 pub(super) fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
+    assert_eq!(crate_num, LOCAL_CRATE);
+
     let mut hcx = tcx.create_stable_hashing_context();
 
     let mut hir_body_nodes: Vec<_> = tcx
-        .index_hir(crate_num)
+        .index_hir(())
         .map
         .iter_enumerated()
         .filter_map(|(def_id, hod)| {

compiler/rustc_middle/src/hir/mod.rs

@@ -13,7 +13,7 @@ use rustc_ast::Attribute;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_hir::def_id::{LocalDefId, LOCAL_CRATE};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::*;
 use rustc_index::vec::IndexVec;
 use rustc_span::DUMMY_SP;
@@ -123,14 +123,14 @@ pub fn provide(providers: &mut Providers) {
         let hir = tcx.hir();
         hir.local_def_id(hir.get_module_parent_node(hir.local_def_id_to_hir_id(id)))
     };
-    providers.hir_crate = |tcx, _| tcx.untracked_crate;
+    providers.hir_crate = |tcx, ()| tcx.untracked_crate;
     providers.index_hir = map::index_hir;
     providers.crate_hash = map::crate_hash;
     providers.hir_module_items = |tcx, id| &tcx.untracked_crate.modules[&id];
-    providers.hir_owner = |tcx, id| tcx.index_hir(LOCAL_CRATE).map[id].signature;
-    providers.hir_owner_nodes = |tcx, id| tcx.index_hir(LOCAL_CRATE).map[id].with_bodies.as_deref();
+    providers.hir_owner = |tcx, id| tcx.index_hir(()).map[id].signature;
+    providers.hir_owner_nodes = |tcx, id| tcx.index_hir(()).map[id].with_bodies.as_deref();
     providers.hir_owner_parent = |tcx, id| {
-        let index = tcx.index_hir(LOCAL_CRATE);
+        let index = tcx.index_hir(());
         index.parenting.get(&id).copied().unwrap_or(CRATE_HIR_ID)
     };
     providers.hir_attrs = |tcx, id| AttributeMap { map: &tcx.untracked_crate.attrs, prefix: id };
@@ -151,4 +151,5 @@ pub fn provide(providers: &mut Providers) {
         }
     };
     providers.opt_def_kind = |tcx, def_id| tcx.hir().opt_def_kind(def_id.expect_local());
+    providers.all_local_trait_impls = |tcx, ()| &tcx.hir_crate(()).trait_impls;
 }

compiler/rustc_middle/src/query/mod.rs

@@ -20,7 +20,7 @@ rustc_queries! {
     /// This is because the `hir_crate` query gives you access to all other items.
     /// To avoid this fate, do not call `tcx.hir().krate()`; instead,
     /// prefer wrappers like `tcx.visit_all_items_in_krate()`.
-    query hir_crate(key: CrateNum) -> &'tcx Crate<'tcx> {
+    query hir_crate(key: ()) -> &'tcx Crate<'tcx> {
         eval_always
         no_hash
         desc { "get the crate HIR" }
@@ -28,7 +28,7 @@ rustc_queries! {
 
     /// The indexed HIR. This can be conveniently accessed by `tcx.hir()`.
     /// Avoid calling this query directly.
-    query index_hir(_: CrateNum) -> &'tcx crate::hir::IndexedHir<'tcx> {
+    query index_hir(_: ()) -> &'tcx crate::hir::IndexedHir<'tcx> {
         eval_always
         no_hash
         desc { "index HIR" }
@@ -965,7 +965,7 @@ rustc_queries! {
     /// Passing in any other crate will cause an ICE.
     ///
     /// [`LOCAL_CRATE`]: rustc_hir::def_id::LOCAL_CRATE
-    query all_local_trait_impls(local_crate: CrateNum) -> &'tcx BTreeMap<DefId, Vec<LocalDefId>> {
+    query all_local_trait_impls(_: ()) -> &'tcx BTreeMap<DefId, Vec<LocalDefId>> {
         desc { "local trait impls" }
     }
 

compiler/rustc_middle/src/ty/mod.rs

@@ -1970,7 +1970,6 @@ pub fn provide(providers: &mut ty::query::Providers) {
     super::util::bug::provide(providers);
     *providers = ty::query::Providers {
         trait_impls_of: trait_def::trait_impls_of_provider,
-        all_local_trait_impls: trait_def::all_local_trait_impls,
         type_uninhabited_from: inhabitedness::type_uninhabited_from,
         const_param_default: consts::const_param_default,
         ..*providers

compiler/rustc_middle/src/ty/trait_def.rs

@@ -4,14 +4,13 @@ use crate::ty::fast_reject;
 use crate::ty::fold::TypeFoldable;
 use crate::ty::{Ty, TyCtxt};
 use rustc_hir as hir;
-use rustc_hir::def_id::{CrateNum, DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
 use rustc_hir::definitions::DefPathHash;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_errors::ErrorReported;
 use rustc_macros::HashStable;
-use std::collections::BTreeMap;
 
 /// A trait's definition with type information.
 #[derive(HashStable)]
@@ -209,14 +208,6 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-// Query provider for `all_local_trait_impls`.
-pub(super) fn all_local_trait_impls<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    krate: CrateNum,
-) -> &'tcx BTreeMap<DefId, Vec<LocalDefId>> {
-    &tcx.hir_crate(krate).trait_impls
-}
-
 // Query provider for `trait_impls_of`.
 pub(super) fn trait_impls_of_provider(tcx: TyCtxt<'_>, trait_id: DefId) -> TraitImpls {
     let mut impls = TraitImpls::default();

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

@@ -12,7 +12,7 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::{def_id::LOCAL_CRATE, source_map::Span};
+use rustc_span::{source_map::Span};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for deriving `Hash` but implementing `PartialEq`
@@ -312,7 +312,7 @@ fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &T
         if ty_subs.non_erasable_generics().next().is_some() {
             let has_copy_impl = cx
                 .tcx
-                .all_local_trait_impls(LOCAL_CRATE)
+                .all_local_trait_impls(())
                 .get(&copy_id)
                 .map_or(false, |impls| {
                     impls