Accept `self` in place of `mod` in use items

[breaking-change]

`mod` is still accepted, but gives a deprecated warning

2 files changed, 5 insertions, 1 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 457085f5cc8..f84ddcf360e 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -546,6 +546,10 @@ impl<'a> Parser<'a> {
     pub fn parse_path_list_item(&mut self) -> ast::PathListItem {
         let lo = self.span.lo;
         let node = if self.eat_keyword(keywords::Mod) {
+            let span = self.last_span;
+            self.span_warn(span, "deprecated syntax; use the `self` keyword now");
+            ast::PathListMod { id: ast::DUMMY_NODE_ID }
+        } else if self.eat_keyword(keywords::Self) {
             ast::PathListMod { id: ast::DUMMY_NODE_ID }
         } else {
             let ident = self.parse_ident();
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 02a03285d3b..877b2c7b7d3 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2540,7 +2540,7 @@ impl<'a> State<'a> {
                             s.print_ident(name)
                         },
                         ast::PathListMod { .. } => {
-                            word(&mut s.s, "mod")
+                            word(&mut s.s, "self")
                         }
                     }
                 }));