Auto merge of #61672 - Centril:rollup-jxo89ir, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #61646 (Remove useless allocations in macro_rules follow logic.)
 - #61658 (remove useless ident() functions in const tests)
 - #61660 (Minimize use of `#![feature(custom_attribute)]`)
 - #61666 (Add test for trait ICE)
 - #61669 ( syntax: Remove `Deref` impl from `Token`)
 - #61670 (Update RLS)

Failed merges:

r? @ghost

6 files changed, 94 insertions, 141 deletions

diff --git a/src/libsyntax/parse/diagnostics.rs b/src/libsyntax/parse/diagnostics.rs
index c4db9a9df45..9d2ac5b4b51 100644
--- a/src/libsyntax/parse/diagnostics.rs
+++ b/src/libsyntax/parse/diagnostics.rs
@@ -729,7 +729,7 @@ impl<'a> Parser<'a> {
         &mut self,
         t: &TokenKind,
     ) -> PResult<'a, bool /* recovered */> {
-        let token_str = pprust::token_to_string(t);
+        let token_str = pprust::token_kind_to_string(t);
         let this_token_str = self.this_token_descr();
         let (prev_sp, sp) = match (&self.token.kind, self.subparser_name) {
             // Point at the end of the macro call when reaching end of macro arguments.
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index e3d959c2c54..2f4c48d4bf9 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1501,7 +1501,7 @@ fn char_at(s: &str, byte: usize) -> char {
 mod tests {
     use super::*;
 
-    use crate::ast::{Ident, CrateConfig};
+    use crate::ast::CrateConfig;
     use crate::symbol::Symbol;
     use crate::source_map::{SourceMap, FilePathMapping};
     use crate::feature_gate::UnstableFeatures;
@@ -1562,7 +1562,7 @@ mod tests {
             assert_eq!(string_reader.next_token(), token::Whitespace);
             let tok1 = string_reader.next_token();
             let tok2 = Token::new(
-                token::Ident(Symbol::intern("fn"), false),
+                mk_ident("fn"),
                 Span::new(BytePos(21), BytePos(23), NO_EXPANSION),
             );
             assert_eq!(tok1.kind, tok2.kind);
@@ -1593,7 +1593,7 @@ mod tests {
 
     // make the identifier by looking up the string in the interner
     fn mk_ident(id: &str) -> TokenKind {
-        TokenKind::from_ast_ident(Ident::from_str(id))
+        token::Ident(Symbol::intern(id), false)
     }
 
     fn mk_lit(kind: token::LitKind, symbol: &str, suffix: Option<&str>) -> TokenKind {
diff --git a/src/libsyntax/parse/lexer/tokentrees.rs b/src/libsyntax/parse/lexer/tokentrees.rs
index b809f99beba..99d9d40a45b 100644
--- a/src/libsyntax/parse/lexer/tokentrees.rs
+++ b/src/libsyntax/parse/lexer/tokentrees.rs
@@ -211,7 +211,7 @@ impl<'a> TokenTreesReader<'a> {
                 let raw = self.string_reader.peek_span_src_raw;
                 self.real_token();
                 let is_joint = raw.hi() == self.string_reader.peek_span_src_raw.lo()
-                    && token::is_op(&self.token);
+                    && self.token.is_op();
                 Ok((tt, if is_joint { Joint } else { NonJoint }))
             }
         }
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 1d708d39a13..cde35681988 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -9,7 +9,7 @@ use crate::parse::parser::emit_unclosed_delims;
 use crate::parse::token::TokenKind;
 use crate::tokenstream::{TokenStream, TokenTree};
 use crate::diagnostics::plugin::ErrorMap;
-use crate::print::pprust::token_to_string;
+use crate::print::pprust;
 
 use errors::{Applicability, FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
 use rustc_data_structures::sync::{Lrc, Lock};
@@ -312,7 +312,7 @@ pub fn maybe_file_to_stream(
             for unmatched in unmatched_braces {
                 let mut db = sess.span_diagnostic.struct_span_err(unmatched.found_span, &format!(
                     "incorrect close delimiter: `{}`",
-                    token_to_string(&token::CloseDelim(unmatched.found_delim)),
+                    pprust::token_kind_to_string(&token::CloseDelim(unmatched.found_delim)),
                 ));
                 db.span_label(unmatched.found_span, "incorrect close delimiter");
                 if let Some(sp) = unmatched.candidate_span {
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 3acd7088145..d9eba3bbadb 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -401,7 +401,7 @@ crate enum TokenType {
 impl TokenType {
     crate fn to_string(&self) -> String {
         match *self {
-            TokenType::Token(ref t) => format!("`{}`", pprust::token_to_string(t)),
+            TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)),
             TokenType::Keyword(kw) => format!("`{}`", kw),
             TokenType::Operator => "an operator".to_string(),
             TokenType::Lifetime => "lifetime".to_string(),
@@ -418,7 +418,7 @@ impl TokenType {
 ///
 /// Types can also be of the form `IDENT(u8, u8) -> u8`, however this assumes
 /// that `IDENT` is not the ident of a fn trait.
-fn can_continue_type_after_non_fn_ident(t: &TokenKind) -> bool {
+fn can_continue_type_after_non_fn_ident(t: &Token) -> bool {
     t == &token::ModSep || t == &token::Lt ||
     t == &token::BinOp(token::Shl)
 }
@@ -586,10 +586,10 @@ impl<'a> Parser<'a> {
         edible: &[TokenKind],
         inedible: &[TokenKind],
     ) -> PResult<'a, bool /* recovered */> {
-        if edible.contains(&self.token) {
+        if edible.contains(&self.token.kind) {
             self.bump();
             Ok(false)
-        } else if inedible.contains(&self.token) {
+        } else if inedible.contains(&self.token.kind) {
             // leave it in the input
             Ok(false)
         } else if self.last_unexpected_token_span == Some(self.token.span) {
@@ -951,7 +951,7 @@ impl<'a> Parser<'a> {
                         Err(mut e) => {
                             // Attempt to keep parsing if it was a similar separator
                             if let Some(ref tokens) = t.similar_tokens() {
-                                if tokens.contains(&self.token) {
+                                if tokens.contains(&self.token.kind) {
                                     self.bump();
                                 }
                             }
@@ -1756,7 +1756,7 @@ impl<'a> Parser<'a> {
     fn parse_path_segment(&mut self, style: PathStyle) -> PResult<'a, PathSegment> {
         let ident = self.parse_path_segment_ident()?;
 
-        let is_args_start = |token: &TokenKind| match *token {
+        let is_args_start = |token: &Token| match token.kind {
             token::Lt | token::BinOp(token::Shl) | token::OpenDelim(token::Paren)
             | token::LArrow => true,
             _ => false,
@@ -2627,9 +2627,11 @@ impl<'a> Parser<'a> {
                     token::Ident(name, _) => name,
                     _ => unreachable!()
                 };
-                let mut err = self.fatal(&format!("unknown macro variable `{}`", name));
-                err.span_label(self.token.span, "unknown macro variable");
-                err.emit();
+                let span = self.prev_span.to(self.token.span);
+                self.diagnostic()
+                    .struct_span_fatal(span, &format!("unknown macro variable `{}`", name))
+                    .span_label(span, "unknown macro variable")
+                    .emit();
                 self.bump();
                 return
             }
@@ -2820,7 +2822,7 @@ impl<'a> Parser<'a> {
                 LhsExpr::AttributesParsed(attrs) => Some(attrs),
                 _ => None,
             };
-            if [token::DotDot, token::DotDotDot, token::DotDotEq].contains(&self.token) {
+            if [token::DotDot, token::DotDotDot, token::DotDotEq].contains(&self.token.kind) {
                 return self.parse_prefix_range_expr(attrs);
             } else {
                 self.parse_prefix_expr(attrs)?
@@ -3097,7 +3099,7 @@ impl<'a> Parser<'a> {
             self.err_dotdotdot_syntax(self.token.span);
         }
 
-        debug_assert!([token::DotDot, token::DotDotDot, token::DotDotEq].contains(&self.token),
+        debug_assert!([token::DotDot, token::DotDotDot, token::DotDotEq].contains(&self.token.kind),
                       "parse_prefix_range_expr: token {:?} is not DotDot/DotDotEq",
                       self.token);
         let tok = self.token.clone();
@@ -7865,7 +7867,7 @@ pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, handler:
     for unmatched in unclosed_delims.iter() {
         let mut err = handler.struct_span_err(unmatched.found_span, &format!(
             "incorrect close delimiter: `{}`",
-            pprust::token_to_string(&token::CloseDelim(unmatched.found_delim)),
+            pprust::token_kind_to_string(&token::CloseDelim(unmatched.found_delim)),
         ));
         err.span_label(unmatched.found_span, "incorrect close delimiter");
         if let Some(sp) = unmatched.candidate_span {
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 28a733728bf..cc34883e2e8 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -17,7 +17,6 @@ use log::info;
 
 use std::fmt;
 use std::mem;
-use std::ops::Deref;
 #[cfg(target_arch = "x86_64")]
 use rustc_data_structures::static_assert_size;
 use rustc_data_structures::sync::Lrc;
@@ -242,20 +241,57 @@ pub struct Token {
 }
 
 impl TokenKind {
-    /// Recovers a `TokenKind` from an `ast::Ident`. This creates a raw identifier if necessary.
-    pub fn from_ast_ident(ident: ast::Ident) -> TokenKind {
-        Ident(ident.name, ident.is_raw_guess())
+    pub fn lit(kind: LitKind, symbol: Symbol, suffix: Option<Symbol>) -> TokenKind {
+        Literal(Lit::new(kind, symbol, suffix))
     }
 
-    crate fn is_like_plus(&self) -> bool {
+    /// Returns tokens that are likely to be typed accidentally instead of the current token.
+    /// Enables better error recovery when the wrong token is found.
+    crate fn similar_tokens(&self) -> Option<Vec<TokenKind>> {
         match *self {
-            BinOp(Plus) | BinOpEq(Plus) => true,
-            _ => false,
+            Comma => Some(vec![Dot, Lt, Semi]),
+            Semi => Some(vec![Colon, Comma]),
+            _ => None
         }
     }
 }
 
 impl Token {
+    crate fn new(kind: TokenKind, span: Span) -> Self {
+        Token { kind, span }
+    }
+
+    /// Some token that will be thrown away later.
+    crate fn dummy() -> Self {
+        Token::new(TokenKind::Whitespace, DUMMY_SP)
+    }
+
+    /// Recovers a `Token` from an `ast::Ident`. This creates a raw identifier if necessary.
+    crate fn from_ast_ident(ident: ast::Ident) -> Self {
+        Token::new(Ident(ident.name, ident.is_raw_guess()), ident.span)
+    }
+
+    /// Return this token by value and leave a dummy token in its place.
+    crate fn take(&mut self) -> Self {
+        mem::replace(self, Token::dummy())
+    }
+
+    crate fn is_op(&self) -> bool {
+        match self.kind {
+            OpenDelim(..) | CloseDelim(..) | Literal(..) | DocComment(..) |
+            Ident(..) | Lifetime(..) | Interpolated(..) |
+            Whitespace | Comment | Shebang(..) | Eof => false,
+            _ => true,
+        }
+    }
+
+    crate fn is_like_plus(&self) -> bool {
+        match self.kind {
+            BinOp(Plus) | BinOpEq(Plus) => true,
+            _ => false,
+        }
+    }
+
     /// Returns `true` if the token can appear at the start of an expression.
     crate fn can_begin_expr(&self) -> bool {
         match self.kind {
@@ -310,12 +346,10 @@ impl Token {
             _ => false,
         }
     }
-}
 
-impl TokenKind {
     /// Returns `true` if the token can appear at the start of a const param.
-    pub fn can_begin_const_arg(&self) -> bool {
-        match self {
+    crate fn can_begin_const_arg(&self) -> bool {
+        match self.kind {
             OpenDelim(Brace) => true,
             Interpolated(ref nt) => match **nt {
                 NtExpr(..) => true,
@@ -326,31 +360,23 @@ impl TokenKind {
             _ => self.can_begin_literal_or_bool(),
         }
     }
-}
 
-impl Token {
     /// Returns `true` if the token can appear at the start of a generic bound.
     crate fn can_begin_bound(&self) -> bool {
         self.is_path_start() || self.is_lifetime() || self.is_keyword(kw::For) ||
         self == &Question || self == &OpenDelim(Paren)
     }
-}
-
-impl TokenKind {
-    pub fn lit(kind: LitKind, symbol: Symbol, suffix: Option<Symbol>) -> TokenKind {
-        Literal(Lit::new(kind, symbol, suffix))
-    }
 
     /// Returns `true` if the token is any literal
     crate fn is_lit(&self) -> bool {
-        match *self {
+        match self.kind {
             Literal(..) => true,
             _           => false,
         }
     }
 
     crate fn expect_lit(&self) -> Lit {
-        match *self {
+        match self.kind {
             Literal(lit) => lit,
             _=> panic!("`expect_lit` called on non-literal"),
         }
@@ -359,7 +385,7 @@ impl TokenKind {
     /// Returns `true` if the token is any literal, a minus (which can prefix a literal,
     /// for example a '-42', or one of the boolean idents).
     crate fn can_begin_literal_or_bool(&self) -> bool {
-        match *self {
+        match self.kind {
             Literal(..)  => true,
             BinOp(Minus) => true,
             Ident(name, false) if name == kw::True => true,
@@ -371,9 +397,7 @@ impl TokenKind {
             _            => false,
         }
     }
-}
 
-impl Token {
     /// Returns an identifier if this token is an identifier.
     pub fn ident(&self) -> Option<(ast::Ident, /* is_raw */ bool)> {
         match self.kind {
@@ -397,49 +421,25 @@ impl Token {
             _ => None,
         }
     }
-}
 
-impl TokenKind {
-    /// Returns an identifier name if this token is an identifier.
-    pub fn ident_name(&self) -> Option<(ast::Name, /* is_raw */ bool)> {
-        match *self {
-            Ident(name, is_raw) => Some((name, is_raw)),
-            Interpolated(ref nt) => match **nt {
-                NtIdent(ident, is_raw) => Some((ident.name, is_raw)),
-                _ => None,
-            },
-            _ => None,
-        }
-    }
-    /// Returns a lifetime name if this token is a lifetime.
-    pub fn lifetime_name(&self) -> Option<ast::Name> {
-        match *self {
-            Lifetime(name) => Some(name),
-            Interpolated(ref nt) => match **nt {
-                NtLifetime(ident) => Some(ident.name),
-                _ => None,
-            },
-            _ => None,
-        }
-    }
     /// Returns `true` if the token is an identifier.
     pub fn is_ident(&self) -> bool {
-        self.ident_name().is_some()
+        self.ident().is_some()
     }
     /// Returns `true` if the token is a lifetime.
     crate fn is_lifetime(&self) -> bool {
-        self.lifetime_name().is_some()
+        self.lifetime().is_some()
     }
 
     /// Returns `true` if the token is a identifier whose name is the given
     /// string slice.
     crate fn is_ident_named(&self, name: Symbol) -> bool {
-        self.ident_name().map_or(false, |(ident_name, _)| ident_name == name)
+        self.ident().map_or(false, |(ident, _)| ident.name == name)
     }
 
     /// Returns `true` if the token is an interpolated path.
     fn is_path(&self) -> bool {
-        if let Interpolated(ref nt) = *self {
+        if let Interpolated(ref nt) = self.kind {
             if let NtPath(..) = **nt {
                 return true;
             }
@@ -456,33 +456,27 @@ impl TokenKind {
     crate fn is_qpath_start(&self) -> bool {
         self == &Lt || self == &BinOp(Shl)
     }
-}
 
-impl Token {
     crate fn is_path_start(&self) -> bool {
         self == &ModSep || self.is_qpath_start() || self.is_path() ||
         self.is_path_segment_keyword() || self.is_ident() && !self.is_reserved_ident()
     }
-}
 
-impl TokenKind {
     /// Returns `true` if the token is a given keyword, `kw`.
     pub fn is_keyword(&self, kw: Symbol) -> bool {
-        self.ident_name().map(|(name, is_raw)| name == kw && !is_raw).unwrap_or(false)
+        self.ident().map(|(id, is_raw)| id.name == kw && !is_raw).unwrap_or(false)
     }
 
-    pub fn is_path_segment_keyword(&self) -> bool {
-        match self.ident_name() {
-            Some((name, false)) => name.is_path_segment_keyword(),
+    crate fn is_path_segment_keyword(&self) -> bool {
+        match self.ident() {
+            Some((id, false)) => id.is_path_segment_keyword(),
             _ => false,
         }
     }
-}
 
-impl Token {
     // Returns true for reserved identifiers used internally for elided lifetimes,
     // unnamed method parameters, crate root module, error recovery etc.
-    pub fn is_special_ident(&self) -> bool {
+    crate fn is_special_ident(&self) -> bool {
         match self.ident() {
             Some((id, false)) => id.is_special(),
             _ => false,
@@ -512,55 +506,53 @@ impl Token {
             _ => false,
         }
     }
-}
 
-impl TokenKind {
-    crate fn glue(self, joint: TokenKind) -> Option<TokenKind> {
-        Some(match self {
-            Eq => match joint {
+    crate fn glue(self, joint: Token) -> Option<Token> {
+        let kind = match self.kind {
+            Eq => match joint.kind {
                 Eq => EqEq,
                 Gt => FatArrow,
                 _ => return None,
             },
-            Lt => match joint {
+            Lt => match joint.kind {
                 Eq => Le,
                 Lt => BinOp(Shl),
                 Le => BinOpEq(Shl),
                 BinOp(Minus) => LArrow,
                 _ => return None,
             },
-            Gt => match joint {
+            Gt => match joint.kind {
                 Eq => Ge,
                 Gt => BinOp(Shr),
                 Ge => BinOpEq(Shr),
                 _ => return None,
             },
-            Not => match joint {
+            Not => match joint.kind {
                 Eq => Ne,
                 _ => return None,
             },
-            BinOp(op) => match joint {
+            BinOp(op) => match joint.kind {
                 Eq => BinOpEq(op),
                 BinOp(And) if op == And => AndAnd,
                 BinOp(Or) if op == Or => OrOr,
                 Gt if op == Minus => RArrow,
                 _ => return None,
             },
-            Dot => match joint {
+            Dot => match joint.kind {
                 Dot => DotDot,
                 DotDot => DotDotDot,
                 _ => return None,
             },
-            DotDot => match joint {
+            DotDot => match joint.kind {
                 Dot => DotDotDot,
                 Eq => DotDotEq,
                 _ => return None,
             },
-            Colon => match joint {
+            Colon => match joint.kind {
                 Colon => ModSep,
                 _ => return None,
             },
-            SingleQuote => match joint {
+            SingleQuote => match joint.kind {
                 Ident(name, false) => Lifetime(Symbol::intern(&format!("'{}", name))),
                 _ => return None,
             },
@@ -570,26 +562,18 @@ impl TokenKind {
             Question | OpenDelim(..) | CloseDelim(..) |
             Literal(..) | Ident(..) | Lifetime(..) | Interpolated(..) | DocComment(..) |
             Whitespace | Comment | Shebang(..) | Eof => return None,
-        })
-    }
+        };
 
-    /// Returns tokens that are likely to be typed accidentally instead of the current token.
-    /// Enables better error recovery when the wrong token is found.
-    crate fn similar_tokens(&self) -> Option<Vec<TokenKind>> {
-        match *self {
-            Comma => Some(vec![Dot, Lt, Semi]),
-            Semi => Some(vec![Colon, Comma]),
-            _ => None
-        }
+        Some(Token::new(kind, self.span.to(joint.span)))
     }
 
     // See comments in `Nonterminal::to_tokenstream` for why we care about
     // *probably* equal here rather than actual equality
-    crate fn probably_equal_for_proc_macro(&self, other: &TokenKind) -> bool {
-        if mem::discriminant(self) != mem::discriminant(other) {
+    crate fn probably_equal_for_proc_macro(&self, other: &Token) -> bool {
+        if mem::discriminant(&self.kind) != mem::discriminant(&other.kind) {
             return false
         }
-        match (self, other) {
+        match (&self.kind, &other.kind) {
             (&Eq, &Eq) |
             (&Lt, &Lt) |
             (&Le, &Le) |
@@ -643,36 +627,12 @@ impl TokenKind {
     }
 }
 
-impl Token {
-    crate fn new(kind: TokenKind, span: Span) -> Self {
-        Token { kind, span }
-    }
-
-    /// Some token that will be thrown away later.
-    crate fn dummy() -> Self {
-        Token::new(TokenKind::Whitespace, DUMMY_SP)
-    }
-
-    /// Return this token by value and leave a dummy token in its place.
-    crate fn take(&mut self) -> Self {
-        mem::replace(self, Token::dummy())
-    }
-}
-
 impl PartialEq<TokenKind> for Token {
     fn eq(&self, rhs: &TokenKind) -> bool {
         self.kind == *rhs
     }
 }
 
-// FIXME: Remove this after all necessary methods are moved from `TokenKind` to `Token`.
-impl Deref for Token {
-    type Target = TokenKind;
-    fn deref(&self) -> &Self::Target {
-        &self.kind
-    }
-}
-
 #[derive(Clone, RustcEncodable, RustcDecodable)]
 /// For interpolation during macro expansion.
 pub enum Nonterminal {
@@ -812,15 +772,6 @@ impl Nonterminal {
     }
 }
 
-crate fn is_op(tok: &TokenKind) -> bool {
-    match *tok {
-        OpenDelim(..) | CloseDelim(..) | Literal(..) | DocComment(..) |
-        Ident(..) | Lifetime(..) | Interpolated(..) |
-        Whitespace | Comment | Shebang(..) | Eof => false,
-        _ => true,
-    }
-}
-
 fn prepend_attrs(sess: &ParseSess,
                  attrs: &[ast::Attribute],
                  tokens: Option<&tokenstream::TokenStream>,