From 05839199190819bf835ba20442ecbc7b06471a8f Mon Sep 17 00:00:00 2001
From: Kyle Huey <khuey@kylehuey.com>
Date: Tue, 22 Mar 2022 12:00:20 -0700
Subject: [PATCH 1/2] LSIF: consolidate references into a single edge where
 possible.

---
 crates/rust-analyzer/src/cli/lsif.rs | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/crates/rust-analyzer/src/cli/lsif.rs b/crates/rust-analyzer/src/cli/lsif.rs
index b9bb335b05..188f9b1380 100644
--- a/crates/rust-analyzer/src/cli/lsif.rs
+++ b/crates/rust-analyzer/src/cli/lsif.rs
@@ -212,19 +212,24 @@ impl LsifManager<'_> {
                 in_v: result_id.into(),
                 out_v: result_set_id.into(),
             }));
-            for x in token.references {
-                let vertex = *self.range_map.get(&x.range).unwrap();
+            let edges = token.references.iter().fold(
+                HashMap::<_, Vec<lsp_types::NumberOrString>>::new(),
+                |mut edges, x| {
+                    let entry =
+                        edges.entry((x.range.file_id, x.is_definition)).or_insert_with(Vec::new);
+                    entry.push((*self.range_map.get(&x.range).unwrap()).into());
+                    edges
+                },
+            );
+            for ((file_id, is_definition), vertices) in edges.into_iter() {
                 self.add_edge(lsif::Edge::Item(lsif::Item {
-                    document: (*self.file_map.get(&x.range.file_id).unwrap()).into(),
-                    property: Some(if x.is_definition {
+                    document: (*self.file_map.get(&file_id).unwrap()).into(),
+                    property: Some(if is_definition {
                         lsif::ItemKind::Definitions
                     } else {
                         lsif::ItemKind::References
                     }),
-                    edge_data: lsif::EdgeDataMultiIn {
-                        in_vs: vec![vertex.into()],
-                        out_v: result_id.into(),
-                    },
+                    edge_data: lsif::EdgeDataMultiIn { in_vs: vertices, out_v: result_id.into() },
                 }));
             }
         }

From af1aa86ac0df3470b379d21531e67fae0e9c942f Mon Sep 17 00:00:00 2001
From: Kyle Huey <khuey@kylehuey.com>
Date: Tue, 22 Mar 2022 12:38:59 -0700
Subject: [PATCH 2/2] Preserve order when grouping references.

---
 crates/rust-analyzer/src/cli/lsif.rs | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/crates/rust-analyzer/src/cli/lsif.rs b/crates/rust-analyzer/src/cli/lsif.rs
index 188f9b1380..5e6d286987 100644
--- a/crates/rust-analyzer/src/cli/lsif.rs
+++ b/crates/rust-analyzer/src/cli/lsif.rs
@@ -212,7 +212,7 @@ impl LsifManager<'_> {
                 in_v: result_id.into(),
                 out_v: result_set_id.into(),
             }));
-            let edges = token.references.iter().fold(
+            let mut edges = token.references.iter().fold(
                 HashMap::<_, Vec<lsp_types::NumberOrString>>::new(),
                 |mut edges, x| {
                     let entry =
@@ -221,16 +221,21 @@ impl LsifManager<'_> {
                     edges
                 },
             );
-            for ((file_id, is_definition), vertices) in edges.into_iter() {
-                self.add_edge(lsif::Edge::Item(lsif::Item {
-                    document: (*self.file_map.get(&file_id).unwrap()).into(),
-                    property: Some(if is_definition {
-                        lsif::ItemKind::Definitions
-                    } else {
-                        lsif::ItemKind::References
-                    }),
-                    edge_data: lsif::EdgeDataMultiIn { in_vs: vertices, out_v: result_id.into() },
-                }));
+            for x in token.references {
+                if let Some(vertices) = edges.remove(&(x.range.file_id, x.is_definition)) {
+                    self.add_edge(lsif::Edge::Item(lsif::Item {
+                        document: (*self.file_map.get(&x.range.file_id).unwrap()).into(),
+                        property: Some(if x.is_definition {
+                            lsif::ItemKind::Definitions
+                        } else {
+                            lsif::ItemKind::References
+                        }),
+                        edge_data: lsif::EdgeDataMultiIn {
+                            in_vs: vertices,
+                            out_v: result_id.into(),
+                        },
+                    }));
+                }
             }
         }
     }