feat(serving): support scoped cross-references (#5530)

This change only adds support to the ScopedReferences in the serving
data, and the actual server will unwrap them into unscoped references. A
future change will support ScopedReferences in the CrossReferences API.

kythe/go/serving/xrefs/xrefs.go

@@ -892,20 +892,23 @@ readLoop:
 			case xrefs.IsDefKind(req.DefinitionKind, grp.Kind, cr.Incomplete):
 				filtered := filter.FilterGroup(grp)
 				reply.Total.Definitions += int64(len(grp.Anchor))
+				reply.Total.Definitions += int64(countRefs(grp.GetScopedReference()))
 				reply.Filtered.Definitions += int64(filtered)
 				if wantMoreCrossRefs {
 					stats.addAnchors(&crs.Definition, grp)
 				}
 			case xrefs.IsDeclKind(req.DeclarationKind, grp.Kind, cr.Incomplete):
 				filtered := filter.FilterGroup(grp)
 				reply.Total.Declarations += int64(len(grp.Anchor))
+				reply.Total.Declarations += int64(countRefs(grp.GetScopedReference()))
 				reply.Filtered.Declarations += int64(filtered)
 				if wantMoreCrossRefs {
 					stats.addAnchors(&crs.Declaration, grp)
 				}
 			case xrefs.IsRefKind(req.ReferenceKind, grp.Kind):
 				filtered := filter.FilterGroup(grp)
 				reply.Total.References += int64(len(grp.Anchor))
+				reply.Total.References += int64(countRefs(grp.GetScopedReference()))
 				reply.Filtered.References += int64(filtered)
 				if wantMoreCrossRefs {
 					stats.addAnchors(&crs.Reference, grp)
@@ -1236,6 +1239,14 @@ func addMergeNode(mergeMap map[string]string, allTickets []string, rootNode, mer
 	return allTickets
 }
 
+func countRefs(rs []*srvpb.PagedCrossReferences_ScopedReference) int {
+	var n int
+	for _, ref := range rs {
+		n += len(ref.GetReference())
+	}
+	return n
+}
+
 func nodeKind(n *srvpb.Node) string {
 	if n == nil {
 		return ""
@@ -1370,6 +1381,10 @@ func (s *refStats) addRelatedNodes(crs *xpb.CrossReferencesReply_CrossReferenceS
 func (s *refStats) addAnchors(to *[]*xpb.CrossReferencesReply_RelatedAnchor, grp *srvpb.PagedCrossReferences_Group) bool {
 	kind := edges.Canonical(grp.Kind)
 	as := grp.Anchor
+	for _, refs := range grp.GetScopedReference() {
+		// TODO(schroederc): make scopes available in API
+		as = append(as, refs.GetReference()...)
+	}
 	fileInfos := makeFileInfoMap(grp.FileInfo)
 
 	if s.total == s.max {

kythe/go/serving/xrefs/xrefs_filter.go

@@ -409,6 +409,8 @@ func (f *corpusPathFilter) FilterGroup(grp *srvpb.PagedCrossReferences_Group) (f
 	var n int
 	grp.Anchor, n = f.filterAnchors(grp.GetAnchor())
 	filtered += n
+	grp.ScopedReference, n = f.filterReferences(grp.GetScopedReference())
+	filtered += n
 	grp.RelatedNode, n = f.filterRelatedNodes(grp.GetRelatedNode())
 	filtered += n
 	grp.Caller, n = f.filterCallers(grp.GetCaller())
@@ -428,6 +430,18 @@ func (f *corpusPathFilter) filterAnchors(as []*srvpb.ExpandedAnchor) ([]*srvpb.E
 	return as[:j], len(as) - j
 }
 
+func (f *corpusPathFilter) filterReferences(rs []*srvpb.PagedCrossReferences_ScopedReference) ([]*srvpb.PagedCrossReferences_ScopedReference, int) {
+	var j int
+	for i, c := range rs {
+		if !f.AllowExpandedAnchor(c.GetScope()) {
+			continue
+		}
+		rs[j] = rs[i]
+		j++
+	}
+	return rs[:j], len(rs) - j
+}
+
 func (f *corpusPathFilter) filterCallers(cs []*srvpb.PagedCrossReferences_Caller) ([]*srvpb.PagedCrossReferences_Caller, int) {
 	var j int
 	for i, c := range cs {

kythe/go/serving/xrefs/xrefs_test.go

@@ -359,35 +359,37 @@ var (
 			Group: []*srvpb.PagedCrossReferences_Group{{
 				BuildConfig: "testConfig",
 				Kind:        "%/kythe/edge/defines/binding",
-				Anchor: []*srvpb.ExpandedAnchor{{
-					Ticket:             "kythe://c?lang=otpl?path=/a/path#27-33",
-					BuildConfiguration: "testConfig",
+				ScopedReference: []*srvpb.PagedCrossReferences_ScopedReference{{
+					Reference: []*srvpb.ExpandedAnchor{{
+						Ticket:             "kythe://c?lang=otpl?path=/a/path#27-33",
+						BuildConfiguration: "testConfig",
 
-					Span: &cpb.Span{
-						Start: &cpb.Point{
-							ByteOffset:   27,
-							LineNumber:   2,
-							ColumnOffset: 10,
-						},
-						End: &cpb.Point{
-							ByteOffset:   33,
-							LineNumber:   3,
-							ColumnOffset: 5,
+						Span: &cpb.Span{
+							Start: &cpb.Point{
+								ByteOffset:   27,
+								LineNumber:   2,
+								ColumnOffset: 10,
+							},
+							End: &cpb.Point{
+								ByteOffset:   33,
+								LineNumber:   3,
+								ColumnOffset: 5,
+							},
 						},
-					},
 
-					SnippetSpan: &cpb.Span{
-						Start: &cpb.Point{
-							ByteOffset: 17,
-							LineNumber: 2,
-						},
-						End: &cpb.Point{
-							ByteOffset:   27,
-							LineNumber:   2,
-							ColumnOffset: 10,
+						SnippetSpan: &cpb.Span{
+							Start: &cpb.Point{
+								ByteOffset: 17,
+								LineNumber: 2,
+							},
+							End: &cpb.Point{
+								ByteOffset:   27,
+								LineNumber:   2,
+								ColumnOffset: 10,
+							},
 						},
-					},
-					Snippet: "here and  ",
+						Snippet: "here and  ",
+					}},
 				}},
 			}},
 			PageIndex: []*srvpb.PagedCrossReferences_PageIndex{{

kythe/proto/serving.proto

@@ -276,6 +276,20 @@ message PagedCrossReferences {
     int32 ordinal = 2;
   }
 
+  // References to the source node with an associated semantic scope.
+  message ScopedReference {
+    // The definition anchor covering the semantic scope.
+    ExpandedAnchor scope = 1;
+    // The semantic ticket for the scope.
+    string semantic_scope = 2;
+
+    // MarkedSource for the scope.
+    kythe.proto.common.MarkedSource marked_source = 3;
+
+    // Specific locations within the scope that reference the source node.
+    repeated ExpandedAnchor reference = 4;
+  }
+
   // Caller of the source node with all associated callsites within the caller.
   message Caller {
     // The anchor covering the caller.
@@ -301,6 +315,7 @@ message PagedCrossReferences {
     repeated ExpandedAnchor anchor = 2;
     repeated RelatedNode related_node = 3;
     repeated Caller caller = 4;
+    repeated ScopedReference scoped_reference = 7;
 
     // List of files referenced in the group
     repeated FileInfo file_info = 6;