Mark incorrect recovered char literals as TyErr to avoid type errors

Author: JohnTitor

src/librustc/ich/impls_syntax.rs

@@ -164,6 +164,7 @@ impl_stable_hash_for!(enum ::syntax::ast::LitIntType {
 impl_stable_hash_for_spanned!(::syntax::ast::LitKind);
 impl_stable_hash_for!(enum ::syntax::ast::LitKind {
     Str(value, style),
+    Err(value),
     ByteStr(value),
     Byte(value),
     Char(value),

src/librustc_mir/hair/constant.rs

@@ -37,6 +37,14 @@ crate fn lit_to_const<'a, 'gcx, 'tcx>(
             let id = tcx.allocate_bytes(s.as_bytes());
             ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, &tcx)
         },
+        LitKind::Err(ref s) => {
+            let s = s.as_str();
+            let id = tcx.allocate_bytes(s.as_bytes());
+            return Ok(ty::Const {
+                val: ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, &tcx),
+                ty: tcx.types.err,
+            });
+        },
         LitKind::ByteStr(ref data) => {
             let id = tcx.allocate_bytes(data);
             ConstValue::Scalar(Scalar::Ptr(id.into()))

src/librustc_typeck/check/mod.rs

@@ -3121,7 +3121,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 opt_ty.unwrap_or_else(
                     || tcx.mk_float_var(self.next_float_var_id()))
             }
-            ast::LitKind::Bool(_) => tcx.types.bool
+            ast::LitKind::Bool(_) => tcx.types.bool,
+            ast::LitKind::Err(_) => tcx.types.err,
         }
     }
 

src/libsyntax/ast.rs

@@ -1285,6 +1285,8 @@ pub enum LitKind {
     FloatUnsuffixed(Symbol),
     /// A boolean literal.
     Bool(bool),
+    /// A recovered character literal that contains mutliple `char`s, most likely a typo.
+    Err(Symbol),
 }
 
 impl LitKind {
@@ -1321,6 +1323,7 @@ impl LitKind {
             | LitKind::ByteStr(..)
             | LitKind::Byte(..)
             | LitKind::Char(..)
+            | LitKind::Err(..)
             | LitKind::Int(_, LitIntType::Unsuffixed)
             | LitKind::FloatUnsuffixed(..)
             | LitKind::Bool(..) => true,

src/libsyntax/attr/mod.rs

@@ -661,6 +661,7 @@ impl LitKind {
             } else {
                 "false"
             })), false),
+            LitKind::Err(val) => Token::Literal(token::Lit::Err(val), None),
         }
     }
 

src/libsyntax/parse/mod.rs

@@ -466,7 +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))),
+       token::Err(i) => (true, Some(LitKind::Err(i))),
 
         // There are some valid suffixes for integer and float literals,
         // so all the handling is done internally.

src/libsyntax/parse/token.rs

@@ -473,8 +473,7 @@ impl Token {
 
             Le | EqEq | Ne | Ge | AndAnd | OrOr | Tilde | BinOpEq(..) | At | DotDotDot |
             DotDotEq | Comma | Semi | ModSep | RArrow | LArrow | FatArrow | Pound | Dollar |
-            Question | OpenDelim(..) | CloseDelim(..) => return None,
-
+            Question | OpenDelim(..) | CloseDelim(..) |
             Literal(..) | Ident(..) | Lifetime(..) | Interpolated(..) | DocComment(..) |
             Whitespace | Comment | Shebang(..) | Eof => return None,
         })

src/libsyntax/print/pprust.rs

@@ -604,6 +604,14 @@ pub trait PrintState<'a> {
         }
         match lit.node {
             ast::LitKind::Str(st, style) => self.print_string(&st.as_str(), style),
+            ast::LitKind::Err(st) => {
+                let st = st.as_str().escape_debug();
+                let mut res = String::with_capacity(st.len() + 2);
+                res.push('\'');
+                res.push_str(&st);
+                res.push('\'');
+                self.writer().word(res)
+            }
             ast::LitKind::Byte(byte) => {
                 let mut res = String::from("b'");
                 res.extend(ascii::escape_default(byte).map(|c| c as char));

src/libsyntax_ext/concat.rs

@@ -23,6 +23,7 @@ pub fn expand_syntax_ext(
         match e.node {
             ast::ExprKind::Lit(ref lit) => match lit.node {
                 ast::LitKind::Str(ref s, _)
+                | ast::LitKind::Err(ref s)
                 | ast::LitKind::Float(ref s, _)
                 | ast::LitKind::FloatUnsuffixed(ref s) => {
                     accumulator.push_str(&s.as_str());