Rollup merge of #33854 - petrochenkov:prefvis, r=eddyb

Apply visit_path to import prefixes by default

Overriding `visit_path` is not enough to visit all paths, some import prefixes are not visited and `visit_path_list_item` need to be overridden as well. This PR removes this catch, it should be less error prone this way. Also, the prefix is visited once now, not repeatedly for each path list item.

r? @eddyb

3 files changed, 8 insertions, 26 deletions

diff --git a/src/librustc/hir/intravisit.rs b/src/librustc/hir/intravisit.rs
index 9b1d2243667..80918ce68e2 100644
--- a/src/librustc/hir/intravisit.rs
+++ b/src/librustc/hir/intravisit.rs
@@ -280,12 +280,9 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                     visitor.visit_path(path, item.id);
                 }
                 ViewPathList(ref prefix, ref list) => {
-                    if !list.is_empty() {
-                        for item in list {
-                            visitor.visit_path_list_item(prefix, item)
-                        }
-                    } else {
-                        visitor.visit_path(prefix, item.id);
+                    visitor.visit_path(prefix, item.id);
+                    for item in list {
+                        visitor.visit_path_list_item(prefix, item)
                     }
                 }
             }
@@ -419,12 +416,8 @@ pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
 }
 
 pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V,
-                                               prefix: &'v Path,
+                                               _prefix: &'v Path,
                                                item: &'v PathListItem) {
-    for segment in &prefix.segments {
-        visitor.visit_path_segment(prefix.span, segment);
-    }
-
     walk_opt_name(visitor, item.span, item.node.name());
     walk_opt_name(visitor, item.span, item.node.rename());
 }
diff --git a/src/librustc_incremental/calculate_svh.rs b/src/librustc_incremental/calculate_svh.rs
index 3dd1b6eb205..a039467c8af 100644
--- a/src/librustc_incremental/calculate_svh.rs
+++ b/src/librustc_incremental/calculate_svh.rs
@@ -401,10 +401,6 @@ mod svh_visitor {
             SawPath.hash(self.st); visit::walk_path(self, path)
         }
 
-        fn visit_path_list_item(&mut self, prefix: &'a Path, item: &'a PathListItem) {
-            SawPath.hash(self.st); visit::walk_path_list_item(self, prefix, item)
-        }
-
         fn visit_block(&mut self, b: &'a Block) {
             SawBlock.hash(self.st); visit::walk_block(self, b)
         }
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 8a02e549d4c..a1d8e056b02 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -233,12 +233,9 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                     visitor.visit_path(path, item.id);
                 }
                 ViewPathList(ref prefix, ref list) => {
-                    if !list.is_empty() {
-                        for item in list {
-                            visitor.visit_path_list_item(prefix, item)
-                        }
-                    } else {
-                        visitor.visit_path(prefix, item.id);
+                    visitor.visit_path(prefix, item.id);
+                    for item in list {
+                        visitor.visit_path_list_item(prefix, item)
                     }
                 }
             }
@@ -368,12 +365,8 @@ pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
     }
 }
 
-pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V, prefix: &'v Path,
+pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V, _prefix: &'v Path,
                                                item: &'v PathListItem) {
-    for segment in &prefix.segments {
-        visitor.visit_path_segment(prefix.span, segment);
-    }
-
     walk_opt_ident(visitor, item.span, item.node.name());
     walk_opt_ident(visitor, item.span, item.node.rename());
 }