Make TraitCandidate generic.

src/librustc/ty/context.rs

@@ -1161,7 +1161,10 @@ 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();
+            let v = v
+                .into_iter()
+                .map(|tc| tc.map_import_ids(|id| hir.definitions().node_to_hir_id(id)))
+                .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};
+use rustc_hir::{Constness, GlobMap, Node, TraitMap};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_macros::HashStable;
 use rustc_serialize::{self, Encodable, Encoder};
@@ -46,7 +46,6 @@ 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;
@@ -123,28 +122,11 @@ 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>,
     pub extern_crate_map: NodeMap<CrateNum>,
-    pub trait_map: TraitMap,
+    pub trait_map: TraitMap<NodeId>,
     pub maybe_unused_trait_imports: NodeSet,
     pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
     pub export_map: ExportMap<NodeId>,

src/librustc_hir/hir.rs

@@ -2608,13 +2608,24 @@ pub type CaptureModeMap = NodeMap<CaptureBy>;
 // has length > 0 if the trait is found through an chain of imports, starting with the
 // import/use statement in the scope where the trait is used.
 #[derive(Clone, Debug)]
-pub struct TraitCandidate {
+pub struct TraitCandidate<ID = HirId> {
     pub def_id: DefId,
-    pub import_ids: SmallVec<[HirId; 1]>,
+    pub import_ids: SmallVec<[ID; 1]>,
+}
+
+impl<ID> TraitCandidate<ID> {
+    pub fn map_import_ids<F, T>(self, f: F) -> TraitCandidate<T>
+    where
+        F: Fn(ID) -> T,
+    {
+        let TraitCandidate { def_id, import_ids } = self;
+        let import_ids = import_ids.into_iter().map(f).collect();
+        TraitCandidate { def_id, import_ids }
+    }
 }
 
 // Trait method resolution
-pub type TraitMap = NodeMap<Vec<TraitCandidate>>;
+pub type TraitMap<ID = HirId> = NodeMap<Vec<TraitCandidate<ID>>>;
 
 // Map from the NodeId of a glob import to a list of items which are actually
 // imported.

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};
@@ -2078,7 +2078,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         &mut self,
         mut ident: Ident,
         ns: Namespace,
-    ) -> Vec<TraitCandidate> {
+    ) -> Vec<TraitCandidate<NodeId>> {
         debug!("(getting traits containing item) looking for '{}'", ident.name);
 
         let mut found_traits = Vec::new();
@@ -2123,7 +2123,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         ident: Ident,
         ns: Namespace,
         module: Module<'a>,
-        found_traits: &mut Vec<TraitCandidate>,
+        found_traits: &mut Vec<TraitCandidate<NodeId>>,
     ) {
         assert!(ns == TypeNS || ns == ValueNS);
         let mut traits = module.traits.borrow_mut();

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, TraitMap};
+use rustc::ty::{self, DefIdTree, ResolverOutputs};
 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;
@@ -865,7 +865,7 @@ pub struct Resolver<'a> {
     /// `CrateNum` resolutions of `extern crate` items.
     extern_crate_map: NodeMap<CrateNum>,
     export_map: ExportMap<NodeId>,
-    trait_map: TraitMap,
+    trait_map: TraitMap<NodeId>,
 
     /// A map from nodes to anonymous modules.
     /// Anonymous modules are pseudo-modules that are implicitly created around items