From 072449c0dc9bd435f002fa7fb531d6819033229e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20K=C3=A5re=20Alsaker?= <john.kare.alsaker@gmail.com>
Date: Sat, 8 Feb 2020 04:14:29 +0100
Subject: [PATCH] Update `trait_impls`

---
 src/librustc/hir/map/mod.rs  | 10 +++-------
 src/librustc/query/mod.rs    |  3 +++
 src/librustc/ty/mod.rs       |  7 +++++--
 src/librustc/ty/query/mod.rs |  1 +
 src/librustc/ty/trait_def.rs | 12 +++++++++++-
 5 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index f9b9c7a3cfe8..1a816e6b2cbe 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -4,7 +4,7 @@ pub use self::definitions::{
 };
 
 use crate::arena::Arena;
-use crate::dep_graph::{DepGraph, DepKind, DepNode, DepNodeIndex};
+use crate::dep_graph::{DepGraph, DepNodeIndex};
 use crate::hir::{HirOwner, HirOwnerItems};
 use crate::middle::cstore::CrateStoreDyn;
 use crate::ty::query::Providers;
@@ -13,7 +13,7 @@ use rustc_ast::ast::{self, Name, NodeId};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::svh::Svh;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefId, DefIndex, LocalDefId};
+use rustc_hir::def_id::{DefId, DefIndex, LocalDefId, LOCAL_CRATE};
 use rustc_hir::intravisit;
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_hir::print::Nested;
@@ -532,11 +532,7 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn trait_impls(&self, trait_did: DefId) -> &'hir [HirId] {
-        self.dep_graph.read(DepNode::new_no_params(DepKind::AllLocalTraitImpls));
-
-        // N.B., intentionally bypass `self.krate()` so that we
-        // do not trigger a read of the whole krate here
-        self.krate.trait_impls.get(&trait_did).map_or(&[], |xs| &xs[..])
+        self.tcx.all_local_trait_impls(LOCAL_CRATE).get(&trait_did).map_or(&[], |xs| &xs[..])
     }
 
     /// Gets the attributes on the crate. This is preferable to
diff --git a/src/librustc/query/mod.rs b/src/librustc/query/mod.rs
index 2a8e34ddc252..5dafa462ca89 100644
--- a/src/librustc/query/mod.rs
+++ b/src/librustc/query/mod.rs
@@ -671,6 +671,9 @@ rustc_queries! {
     }
 
     TypeChecking {
+        query all_local_trait_impls(key: CrateNum) -> &'tcx BTreeMap<DefId, Vec<hir::HirId>> {
+            desc { "local trait impls" }
+        }
         query trait_impls_of(key: DefId) -> &'tcx ty::trait_def::TraitImpls {
             desc { |tcx| "trait impls of `{}`", tcx.def_path_str(key) }
         }
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index c2697570dda2..d3c4ddf1ed30 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -3142,8 +3142,11 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
     context::provide(providers);
     erase_regions::provide(providers);
     layout::provide(providers);
-    *providers =
-        ty::query::Providers { trait_impls_of: trait_def::trait_impls_of_provider, ..*providers };
+    *providers = ty::query::Providers {
+        trait_impls_of: trait_def::trait_impls_of_provider,
+        all_local_trait_impls: trait_def::all_local_trait_impls,
+        ..*providers
+    };
 }
 
 /// A map for the local crate mapping each type to a vector of its
diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs
index b6976221ef7d..3dbcf9228d23 100644
--- a/src/librustc/ty/query/mod.rs
+++ b/src/librustc/ty/query/mod.rs
@@ -56,6 +56,7 @@ use rustc_attr as attr;
 use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 use std::borrow::Cow;
+use std::collections::BTreeMap;
 use std::convert::TryFrom;
 use std::ops::Deref;
 use std::sync::Arc;
diff --git a/src/librustc/ty/trait_def.rs b/src/librustc/ty/trait_def.rs
index 0cf1c397648e..91a99ec43e6a 100644
--- a/src/librustc/ty/trait_def.rs
+++ b/src/librustc/ty/trait_def.rs
@@ -5,11 +5,13 @@ 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::DefId;
+use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_hir::HirId;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::HashStable;
+use std::collections::BTreeMap;
 
 /// A trait's definition with type information.
 #[derive(HashStable)]
@@ -146,6 +148,14 @@ 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<HirId>> {
+    &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();