Remove trivia tokens

compiler/rustc_ast/src/token.rs

@@ -251,17 +251,6 @@ pub enum TokenKind {
     /// similarly to symbols in string literal tokens.
     DocComment(CommentKind, ast::AttrStyle, Symbol),
 
-    // Junk. These carry no data because we don't really care about the data
-    // they *would* carry, and don't really want to allocate a new ident for
-    // them. Instead, users could extract that from the associated span.
-    /// Whitespace.
-    Whitespace,
-    /// A comment.
-    Comment,
-    Shebang(Symbol),
-    /// A completely invalid token which should be skipped.
-    Unknown(Symbol),
-
     Eof,
 }
 
@@ -331,7 +320,7 @@ impl Token {
 
     /// Some token that will be thrown away later.
     pub fn dummy() -> Self {
-        Token::new(TokenKind::Whitespace, DUMMY_SP)
+        Token::new(TokenKind::Question, DUMMY_SP)
     }
 
     /// Recovers a `Token` from an `Ident`. This creates a raw identifier if necessary.
@@ -360,7 +349,7 @@ impl Token {
     pub fn is_op(&self) -> bool {
         match self.kind {
             OpenDelim(..) | CloseDelim(..) | Literal(..) | DocComment(..) | Ident(..)
-            | Lifetime(..) | Interpolated(..) | Whitespace | Comment | Shebang(..) | Eof => false,
+            | Lifetime(..) | Interpolated(..) | Eof => false,
             _ => true,
         }
     }
@@ -676,8 +665,7 @@ impl Token {
             Le | EqEq | Ne | Ge | AndAnd | OrOr | Tilde | BinOpEq(..) | At | DotDotDot
             | DotDotEq | Comma | Semi | ModSep | RArrow | LArrow | FatArrow | Pound | Dollar
             | Question | OpenDelim(..) | CloseDelim(..) | Literal(..) | Ident(..)
-            | Lifetime(..) | Interpolated(..) | DocComment(..) | Whitespace | Comment
+            | Lifetime(..) | Interpolated(..) | DocComment(..) | Eof => return None,
-            | Shebang(..) | Unknown(..) | Eof => return None,
         };
 
         Some(Token::new(kind, self.span.to(joint.span)))

compiler/rustc_ast_pretty/src/pprust.rs

@@ -289,10 +289,6 @@ fn token_kind_to_string_ext(tok: &TokenKind, convert_dollar_crate: Option<Span>)
             doc_comment_to_string(comment_kind, attr_style, data)
         }
         token::Eof => "<eof>".to_string(),
-        token::Whitespace => " ".to_string(),
-        token::Comment => "/* */".to_string(),
-        token::Shebang(s) => format!("/* shebang: {}*/", s),
-        token::Unknown(s) => s.to_string(),
 
         token::Interpolated(ref nt) => nonterminal_to_string(nt),
     }

compiler/rustc_expand/src/proc_macro_server.rs

@@ -189,7 +189,7 @@ impl FromInternal<(TreeAndJoint, &'_ ParseSess, &'_ mut Vec<Self>)>
             }
 
             OpenDelim(..) | CloseDelim(..) => unreachable!(),
-            Whitespace | Comment | Shebang(..) | Unknown(..) | Eof => unreachable!(),
+            Eof => unreachable!(),
         }
     }
 }

compiler/rustc_parse/src/lexer/unicode_chars.rs

@@ -303,7 +303,7 @@ const UNICODE_ARRAY: &[(char, &str, char)] = &[
 // However, we should first remove compound tokens like `<<` from `rustc_lexer`, and then add
 // fancier error recovery to it, as there will be less overall work to do this way.
 const ASCII_ARRAY: &[(char, &str, Option<token::TokenKind>)] = &[
-    (' ', "Space", Some(token::Whitespace)),
+    (' ', "Space", None),
     ('_', "Underscore", Some(token::Ident(kw::Underscore, false))),
     ('-', "Minus/Hyphen", Some(token::BinOp(token::Minus))),
     (',', "Comma", Some(token::Comma)),

compiler/rustc_parse/src/lib.rs

@@ -348,9 +348,6 @@ pub fn tokenstream_probably_equal_for_proc_macro(
                 | token::CloseDelim(DelimToken::NoDelim)
                 // The pretty printer collapses many semicolons into one.
                 | token::Semi
-                // The pretty printer collapses whitespace arbitrarily and can
-                // introduce whitespace from `NoDelim`.
-                | token::Whitespace
                 // The pretty printer can turn `$crate` into `::crate_name`
                 | token::ModSep = token.kind {
                 return false;
@@ -506,8 +503,6 @@ fn token_probably_equal_for_proc_macro(first: &Token, other: &Token) -> bool {
         | (&Pound, &Pound)
         | (&Dollar, &Dollar)
         | (&Question, &Question)
-        | (&Whitespace, &Whitespace)
-        | (&Comment, &Comment)
         | (&Eof, &Eof) => true,
 
         (&BinOp(a), &BinOp(b)) | (&BinOpEq(a), &BinOpEq(b)) => a == b,
@@ -516,8 +511,6 @@ fn token_probably_equal_for_proc_macro(first: &Token, other: &Token) -> bool {
 
         (&DocComment(a1, a2, a3), &DocComment(b1, b2, b3)) => a1 == b1 && a2 == b2 && a3 == b3,
 
-        (&Shebang(a), &Shebang(b)) => a == b,
-
         (&Literal(a), &Literal(b)) => a == b,
 
         (&Lifetime(a), &Lifetime(b)) => a == b,