1 files changed, 19 insertions, 2 deletions
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index ffe68289d52..1fc5aed7e7a 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -647,7 +647,7 @@ fn check_matcher_core(sess: &ParseSess,
                     let msg = format!("invalid fragment specifier `{}`", bad_frag);
                     sess.span_diagnostic.struct_span_err(token.span(), &msg)
                         .help("valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, \
-                              `pat`, `ty`, `path`, `meta`, `tt`, `item` and `vis`")
+                              `pat`, `ty`, `literal`, `path`, `meta`, `tt`, `item` and `vis`")
                         .emit();
                     // (This eliminates false positives and duplicates
                     // from error messages.)
@@ -784,6 +784,7 @@ fn frag_can_be_followed_by_any(frag: &str) -> bool {
         "item"     | // always terminated by `}` or `;`
         "block"    | // exactly one token tree
         "ident"    | // exactly one token tree
+        "literal"  | // exactly one token tree
         "meta"     | // exactly one token tree
         "lifetime" | // exactly one token tree
         "tt" =>   // exactly one token tree
@@ -850,6 +851,10 @@ fn is_in_follow(tok: &quoted::TokenTree, frag: &str) -> Result<bool, (String, &'
                 // being a single token, idents and lifetimes are harmless
                 Ok(true)
             },
+            "literal" => {
+                // literals may be of a single token, or two tokens (negative numbers)
+                Ok(true)
+            },
             "meta" | "tt" => {
                 // being either a single token or a delimited sequence, tt is
                 // harmless
@@ -873,7 +878,7 @@ fn is_in_follow(tok: &quoted::TokenTree, frag: &str) -> Result<bool, (String, &'
             _ => Err((format!("invalid fragment specifier `{}`", frag),
                      "valid fragment specifiers are `ident`, `block`, \
                       `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt`, \
-                      `item` and `vis`"))
+                      `literal`, `item` and `vis`"))
         }
     }
 }
@@ -913,6 +918,18 @@ fn is_legal_fragment_specifier(sess: &ParseSess,
             }
             true
         },
+        "literal" => {
+            if !features.macro_literal_matcher &&
+               !attr::contains_name(attrs, "allow_internal_unstable") {
+                let explain = feature_gate::EXPLAIN_LITERAL_MATCHER;
+                emit_feature_err(sess,
+                                 "macro_literal_matcher",
+                                 frag_span,
+                                 GateIssue::Language,
+                                 explain);
+            }
+            true
+        },
         "vis" => {
             if !features.macro_vis_matcher &&
                !attr::contains_name(attrs, "allow_internal_unstable") {