Add new literal type Err

src/librustc/ich/impls_syntax.rs

@@ -329,6 +329,7 @@ fn hash_token<'a, 'gcx, W: StableHasherResult>(
             match *lit {
                 token::Lit::Byte(val) |
                 token::Lit::Char(val) |
+                token::Lit::Err(val) |
                 token::Lit::Integer(val) |
                 token::Lit::Float(val) |
                 token::Lit::Str_(val) |

src/libsyntax/ext/quote.rs

@@ -646,6 +646,7 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
 
         token::Literal(token::Byte(i), suf) => return mk_lit!("Byte", suf, i),
         token::Literal(token::Char(i), suf) => return mk_lit!("Char", suf, i),
+        token::Literal(token::Err(i), suf) => return mk_lit!("Err", suf, i),
         token::Literal(token::Integer(i), suf) => return mk_lit!("Integer", suf, i),
         token::Literal(token::Float(i), suf) => return mk_lit!("Float", suf, i),
         token::Literal(token::Str_(i), suf) => return mk_lit!("Str_", suf, i),

src/libsyntax/parse/mod.rs

@@ -466,6 +466,7 @@ crate fn lit_token(lit: token::Lit, suf: Option<Symbol>, diag: Option<(Span, &Ha
     match lit {
        token::Byte(i) => (true, Some(LitKind::Byte(byte_lit(&i.as_str()).0))),
        token::Char(i) => (true, Some(LitKind::Char(char_lit(&i.as_str(), diag).0))),
+       token::Err(i) => (true, Some(LitKind::Char(char_lit(&i.as_str(), diag).0))),
 
         // There are some valid suffixes for integer and float literals,
         // so all the handling is done internally.

src/libsyntax/parse/token.rs

@@ -60,6 +60,7 @@ impl DelimToken {
 pub enum Lit {
     Byte(ast::Name),
     Char(ast::Name),
+    Err(ast::Name),
     Integer(ast::Name),
     Float(ast::Name),
     Str_(ast::Name),
@@ -73,6 +74,7 @@ impl Lit {
         match *self {
             Byte(_) => "byte literal",
             Char(_) => "char literal",
+            Err(_) => "error literal",
             Integer(_) => "integer literal",
             Float(_) => "float literal",
             Str_(_) | StrRaw(..) => "string literal",

src/libsyntax/print/pprust.rs

@@ -224,6 +224,7 @@ pub fn token_to_string(tok: &Token) -> String {
             let mut out = match lit {
                 token::Byte(b)           => format!("b'{}'", b),
                 token::Char(c)           => format!("'{}'", c),
+                token::Err(c)            => format!("'{}'", c),
                 token::Float(c)          |
                 token::Integer(c)        => c.to_string(),
                 token::Str_(s)           => format!("\"{}\"", s),