Use HirId in TraitCandidate.

src/librustc/ich/impls_hir.rs

@@ -270,7 +270,6 @@ impl<'a> ToStableHashKey<StableHashingContext<'a>> for hir::TraitCandidate {
 
         let import_keys = import_ids
             .iter()
-            .map(|node_id| hcx.node_to_hir_id(*node_id))
             .map(|hir_id| (hcx.local_def_path_hash(hir_id.owner), hir_id.local_id))
             .collect();
         (hcx.def_path_hash(*def_id), import_keys)

src/librustc/ty/context.rs

@@ -1161,6 +1161,7 @@ impl<'tcx> TyCtxt<'tcx> {
         for (k, v) in resolutions.trait_map {
             let hir_id = hir.node_to_hir_id(k);
             let map = trait_map.entry(hir_id.owner).or_default();
+            let v = v.into_iter().map(|tc| tc.node_to_hir_id(&hir.definitions())).collect();
             map.insert(hir_id.local_id, StableVec::new(v));
         }
 

src/librustc/ty/mod.rs

@@ -35,7 +35,7 @@ use rustc_data_structures::sync::{self, par_iter, Lrc, ParallelIterator};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
-use rustc_hir::{Constness, GlobMap, Node, TraitMap};
+use rustc_hir::{Constness, GlobMap, Node};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_macros::HashStable;
 use rustc_serialize::{self, Encodable, Encoder};
@@ -46,6 +46,7 @@ use rustc_target::abi::Align;
 use syntax::ast::{self, Ident, Name};
 use syntax::node_id::{NodeId, NodeMap, NodeSet};
 
+use smallvec::SmallVec;
 use std::cell::RefCell;
 use std::cmp::{self, Ordering};
 use std::fmt;
@@ -122,6 +123,23 @@ mod sty;
 
 // Data types
 
+#[derive(Clone, Debug)]
+pub struct TraitCandidate {
+    pub def_id: DefId,
+    pub import_ids: SmallVec<[NodeId; 1]>,
+}
+
+impl TraitCandidate {
+    fn node_to_hir_id(self, definitions: &hir_map::Definitions) -> hir::TraitCandidate {
+        let TraitCandidate { def_id, import_ids } = self;
+        let import_ids =
+            import_ids.into_iter().map(|node_id| definitions.node_to_hir_id(node_id)).collect();
+        hir::TraitCandidate { def_id, import_ids }
+    }
+}
+
+pub type TraitMap = NodeMap<Vec<TraitCandidate>>;
+
 pub struct ResolverOutputs {
     pub definitions: hir_map::Definitions,
     pub cstore: Box<CrateStoreDyn>,

src/librustc_hir/hir.rs

@@ -16,7 +16,7 @@ use rustc_span::source_map::{SourceMap, Spanned};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{MultiSpan, Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
-use syntax::ast::{self, AsmDialect, CrateSugar, Ident, Name, NodeId};
+use syntax::ast::{self, AsmDialect, CrateSugar, Ident, Name};
 use syntax::ast::{AttrVec, Attribute, FloatTy, IntTy, Label, LitKind, StrStyle, UintTy};
 pub use syntax::ast::{BorrowKind, ImplPolarity, IsAuto};
 pub use syntax::ast::{CaptureBy, Movability, Mutability};
@@ -2610,7 +2610,7 @@ pub type CaptureModeMap = NodeMap<CaptureBy>;
 #[derive(Clone, Debug)]
 pub struct TraitCandidate {
     pub def_id: DefId,
-    pub import_ids: SmallVec<[NodeId; 1]>,
+    pub import_ids: SmallVec<[HirId; 1]>,
 }
 
 // Trait method resolution

src/librustc_resolve/late.rs

@@ -11,13 +11,13 @@ use crate::{path_names_to_string, BindingError, CrateLint, LexicalScopeBinding};
 use crate::{Module, ModuleOrUniformRoot, NameBindingKind, ParentScope, PathResult};
 use crate::{ResolutionError, Resolver, Segment, UseError};
 
+use rustc::ty::TraitCandidate;
 use rustc::{bug, lint, span_bug};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::DiagnosticId;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, DefKind, PartialRes, PerNS};
 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
-use rustc_hir::TraitCandidate;
 use rustc_span::symbol::{kw, sym};
 use rustc_span::Span;
 use smallvec::{smallvec, SmallVec};

src/librustc_resolve/lib.rs

@@ -22,7 +22,7 @@ use rustc::lint;
 use rustc::middle::cstore::{CrateStore, MetadataLoaderDyn};
 use rustc::span_bug;
 use rustc::ty::query::Providers;
-use rustc::ty::{self, DefIdTree, ResolverOutputs};
+use rustc::ty::{self, DefIdTree, ResolverOutputs, TraitMap};
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_data_structures::ptr_key::PtrKey;
@@ -32,8 +32,8 @@ use rustc_expand::base::SyntaxExtension;
 use rustc_hir::def::Namespace::*;
 use rustc_hir::def::{self, CtorOf, DefKind, NonMacroAttrKind, PartialRes};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, CRATE_DEF_INDEX, LOCAL_CRATE};
+use rustc_hir::GlobMap;
 use rustc_hir::PrimTy::{self, Bool, Char, Float, Int, Str, Uint};
-use rustc_hir::{GlobMap, TraitMap};
 use rustc_metadata::creader::{CStore, CrateLoader};
 use rustc_session::lint::{BuiltinLintDiagnostics, LintBuffer};
 use rustc_session::Session;

src/librustc_typeck/check/method/probe.rs

@@ -902,13 +902,10 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             for trait_candidate in applicable_traits.iter() {
                 let trait_did = trait_candidate.def_id;
                 if duplicates.insert(trait_did) {
-                    let import_ids = trait_candidate
-                        .import_ids
-                        .iter()
-                        .map(|node_id| self.fcx.tcx.hir().node_to_hir_id(*node_id))
-                        .collect();
-                    let result =
-                        self.assemble_extension_candidates_for_trait(import_ids, trait_did);
+                    let result = self.assemble_extension_candidates_for_trait(
+                        &trait_candidate.import_ids,
+                        trait_did,
+                    );
                     result?;
                 }
             }
@@ -920,7 +917,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let mut duplicates = FxHashSet::default();
         for trait_info in suggest::all_traits(self.tcx) {
             if duplicates.insert(trait_info.def_id) {
-                self.assemble_extension_candidates_for_trait(smallvec![], trait_info.def_id)?;
+                self.assemble_extension_candidates_for_trait(&smallvec![], trait_info.def_id)?;
             }
         }
         Ok(())
@@ -959,7 +956,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
     fn assemble_extension_candidates_for_trait(
         &mut self,
-        import_ids: SmallVec<[hir::HirId; 1]>,
+        import_ids: &SmallVec<[hir::HirId; 1]>,
         trait_def_id: DefId,
     ) -> Result<(), MethodError<'tcx>> {
         debug!("assemble_extension_candidates_for_trait(trait_def_id={:?})", trait_def_id);