Impl Copy for Token and TokenKind.

Author: nnethercote

compiler/rustc_ast/src/token.rs

@@ -278,7 +278,7 @@ impl From<IdentIsRaw> for bool {
     }
 }
 
-#[derive(Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub enum TokenKind {
     /* Expression-operator symbols. */
     /// `=`
@@ -376,7 +376,7 @@ pub enum TokenKind {
     Eof,
 }
 
-#[derive(Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub struct Token {
     pub kind: TokenKind,
     pub span: Span,

compiler/rustc_ast/src/tokenstream.rs

@@ -485,7 +485,7 @@ impl TokenStream {
                 Delimiter::Invisible(InvisibleOrigin::FlattenToken),
                 TokenStream::token_alone(token::Lifetime(ident.name), ident.span),
             ),
-            _ => TokenTree::Token(token.clone(), spacing),
+            _ => TokenTree::Token(*token, spacing),
         }
     }
 

compiler/rustc_expand/src/mbe/diagnostics.rs

@@ -153,7 +153,7 @@ impl<'a, 'cx, 'matcher> Tracker<'matcher> for CollectTrackerAndEmitter<'a, 'cx,
                     .map_or(true, |failure| failure.is_better_position(*approx_position))
                 {
                     self.best_failure = Some(BestFailure {
-                        token: token.clone(),
+                        token: *token,
                         position_in_tokenstream: *approx_position,
                         msg,
                         remaining_matcher: self

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -181,7 +181,7 @@ pub(super) fn compute_locs(matcher: &[TokenTree]) -> Vec<MatcherLoc> {
         for tt in tts {
             match tt {
                 TokenTree::Token(token) => {
-                    locs.push(MatcherLoc::Token { token: token.clone() });
+                    locs.push(MatcherLoc::Token { token: *token });
                 }
                 TokenTree::Delimited(span, _, delimited) => {
                     let open_token = Token::new(token::OpenDelim(delimited.delim), span.open);
@@ -645,7 +645,7 @@ impl TtParser {
                     // There are no possible next positions AND we aren't waiting for the black-box
                     // parser: syntax error.
                     return Failure(T::build_failure(
-                        parser.token.clone(),
+                        parser.token,
                         parser.approx_token_stream_pos(),
                         "no rules expected this token in macro call",
                     ));

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -787,7 +787,7 @@ impl<'tt> FirstSets<'tt> {
                         // token could be the separator token itself.
 
                         if let (Some(sep), true) = (&seq_rep.separator, subfirst.maybe_empty) {
-                            first.add_one_maybe(TtHandle::from_token(sep.clone()));
+                            first.add_one_maybe(TtHandle::from_token(*sep));
                         }
 
                         // Reverse scan: Sequence comes before `first`.
@@ -850,7 +850,7 @@ impl<'tt> FirstSets<'tt> {
                     // If the sequence contents can be empty, then the first
                     // token could be the separator token itself.
                     if let (Some(sep), true) = (&seq_rep.separator, subfirst.maybe_empty) {
-                        first.add_one_maybe(TtHandle::from_token(sep.clone()));
+                        first.add_one_maybe(TtHandle::from_token(*sep));
                     }
 
                     assert!(first.maybe_empty);
@@ -926,7 +926,7 @@ impl<'tt> Clone for TtHandle<'tt> {
             // This variant *must* contain a `mbe::TokenTree::Token`, and not
             // any other variant of `mbe::TokenTree`.
             TtHandle::Token(mbe::TokenTree::Token(tok)) => {
-                TtHandle::Token(mbe::TokenTree::Token(tok.clone()))
+                TtHandle::Token(mbe::TokenTree::Token(*tok))
             }
 
             _ => unreachable!(),
@@ -1102,7 +1102,7 @@ fn check_matcher_core<'tt>(
                 let mut new;
                 let my_suffix = if let Some(sep) = &seq_rep.separator {
                     new = suffix_first.clone();
-                    new.add_one_maybe(TtHandle::from_token(sep.clone()));
+                    new.add_one_maybe(TtHandle::from_token(*sep));
                     &new
                 } else {
                     &suffix_first

compiler/rustc_expand/src/mbe/quoted.rs

@@ -258,7 +258,7 @@ fn parse_tree<'a>(
         }
 
         // `tree` is an arbitrary token. Keep it.
-        tokenstream::TokenTree::Token(token, _) => TokenTree::Token(token.clone()),
+        tokenstream::TokenTree::Token(token, _) => TokenTree::Token(*token),
 
         // `tree` is the beginning of a delimited set of tokens (e.g., `(` or `{`). We need to
         // descend into the delimited set and further parse it.
@@ -296,7 +296,7 @@ fn parse_kleene_op<'a>(
     match input.next() {
         Some(tokenstream::TokenTree::Token(token, _)) => match kleene_op(token) {
             Some(op) => Ok(Ok((op, token.span))),
-            None => Ok(Err(token.clone())),
+            None => Ok(Err(*token)),
         },
         tree => Err(tree.map_or(span, tokenstream::TokenTree::span)),
     }

compiler/rustc_expand/src/mbe/transcribe.rs

@@ -155,7 +155,7 @@ pub(super) fn transcribe<'a>(
                 if repeat_idx < repeat_len {
                     frame.idx = 0;
                     if let Some(sep) = sep {
-                        result.push(TokenTree::Token(sep.clone(), Spacing::Alone));
+                        result.push(TokenTree::Token(*sep, Spacing::Alone));
                     }
                     continue;
                 }
@@ -364,7 +364,7 @@ pub(super) fn transcribe<'a>(
             // Nothing much to do here. Just push the token to the result, being careful to
             // preserve syntax context.
             mbe::TokenTree::Token(token) => {
-                let mut token = token.clone();
+                let mut token = *token;
                 mut_visit::visit_token(&mut token, &mut marker);
                 let tt = TokenTree::Token(token, Spacing::Alone);
                 result.push(tt);

compiler/rustc_parse/src/lexer/unicode_chars.rs

@@ -376,7 +376,7 @@ pub(super) fn check_for_substitution(
             ascii_name,
         })
     };
-    (token.clone(), sugg)
+    (*token, sugg)
 }
 
 /// Extract string if found at current position with given delimiters

compiler/rustc_parse/src/parser/attr_wrapper.rs

@@ -104,13 +104,12 @@ impl ToAttrTokenStream for LazyAttrTokenStreamImpl {
         // produce an empty `TokenStream` if no calls were made, and omit the
         // final token otherwise.
         let mut cursor_snapshot = self.cursor_snapshot.clone();
-        let tokens =
-            std::iter::once((FlatToken::Token(self.start_token.0.clone()), self.start_token.1))
-                .chain(std::iter::repeat_with(|| {
-                    let token = cursor_snapshot.next();
-                    (FlatToken::Token(token.0), token.1)
-                }))
-                .take(self.num_calls);
+        let tokens = std::iter::once((FlatToken::Token(self.start_token.0), self.start_token.1))
+            .chain(std::iter::repeat_with(|| {
+                let token = cursor_snapshot.next();
+                (FlatToken::Token(token.0), token.1)
+            }))
+            .take(self.num_calls);
 
         if !self.replace_ranges.is_empty() {
             let mut tokens: Vec<_> = tokens.collect();
@@ -211,7 +210,7 @@ impl<'a> Parser<'a> {
             return Ok(f(self, attrs.attrs)?.0);
         }
 
-        let start_token = (self.token.clone(), self.token_spacing);
+        let start_token = (self.token, self.token_spacing);
         let cursor_snapshot = self.token_cursor.clone();
         let start_pos = self.num_bump_calls;
 

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -287,7 +287,7 @@ impl<'a> Parser<'a> {
         let mut recovered_ident = None;
         // we take this here so that the correct original token is retained in
         // the diagnostic, regardless of eager recovery.
-        let bad_token = self.token.clone();
+        let bad_token = self.token;
 
         // suggest prepending a keyword in identifier position with `r#`
         let suggest_raw = if let Some((ident, IdentIsRaw::No)) = self.token.ident()
@@ -347,7 +347,7 @@ impl<'a> Parser<'a> {
             // if the previous token is a valid keyword
             // that might use a generic, then suggest a correct
             // generic placement (later on)
-            let maybe_keyword = self.prev_token.clone();
+            let maybe_keyword = self.prev_token;
             if valid_prev_keywords.into_iter().any(|x| maybe_keyword.is_keyword(x)) {
                 // if we have a valid keyword, attempt to parse generics
                 // also obtain the keywords symbol
@@ -463,7 +463,7 @@ impl<'a> Parser<'a> {
                     false
                 }
 
-                if **token != parser::TokenType::Token(self.token.kind.clone()) {
+                if **token != parser::TokenType::Token(self.token.kind) {
                     let eq = is_ident_eq_keyword(&self.token.kind, &token);
                     // If the suggestion is a keyword and the found token is an ident,
                     // the content of which are equal to the suggestion's content,
@@ -527,7 +527,7 @@ impl<'a> Parser<'a> {
                 //   let y = 42;
                 let guar = self.dcx().emit_err(ExpectedSemi {
                     span: self.token.span,
-                    token: self.token.clone(),
+                    token: self.token,
                     unexpected_token_label: None,
                     sugg: ExpectedSemiSugg::ChangeToSemi(self.token.span),
                 });
@@ -552,7 +552,7 @@ impl<'a> Parser<'a> {
                 let span = self.prev_token.span.shrink_to_hi();
                 let guar = self.dcx().emit_err(ExpectedSemi {
                     span,
-                    token: self.token.clone(),
+                    token: self.token,
                     unexpected_token_label: Some(self.token.span),
                     sugg: ExpectedSemiSugg::AddSemi(span),
                 });
@@ -748,7 +748,7 @@ impl<'a> Parser<'a> {
         let span = self.prev_token.span.shrink_to_hi();
         let mut err = self.dcx().create_err(ExpectedSemi {
             span,
-            token: self.token.clone(),
+            token: self.token,
             unexpected_token_label: Some(self.token.span),
             sugg: ExpectedSemiSugg::AddSemi(span),
         });
@@ -2371,7 +2371,7 @@ impl<'a> Parser<'a> {
         // code was interpreted. This helps the user realize when a macro argument of one type is
         // later reinterpreted as a different type, like `$x:expr` being reinterpreted as `$x:pat`
         // in a subsequent macro invocation (#71039).
-        let mut tok = self.token.clone();
+        let mut tok = self.token;
         let mut labels = vec![];
         while let TokenKind::Interpolated(nt) = &tok.kind {
             let tokens = nt.tokens();
@@ -2381,7 +2381,7 @@ impl<'a> Parser<'a> {
                 && let tokens = tokens.0.deref()
                 && let [AttrTokenTree::Token(token, _)] = &tokens[..]
             {
-                tok = token.clone();
+                tok = token;
             } else {
                 break;
             }

compiler/rustc_parse/src/parser/expr.rs

@@ -434,7 +434,7 @@ impl<'a> Parser<'a> {
     fn error_found_expr_would_be_stmt(&self, lhs: &Expr) {
         self.dcx().emit_err(errors::FoundExprWouldBeStmt {
             span: self.token.span,
-            token: self.token.clone(),
+            token: self.token,
             suggestion: ExprParenthesesNeeded::surrounding(lhs.span),
         });
     }
@@ -521,7 +521,7 @@ impl<'a> Parser<'a> {
         cur_op_span: Span,
     ) -> PResult<'a, P<Expr>> {
         let rhs = if self.is_at_start_of_range_notation_rhs() {
-            let maybe_lt = self.token.clone();
+            let maybe_lt = self.token;
             Some(
                 self.parse_expr_assoc_with(prec + 1, LhsExpr::NotYetParsed)
                     .map_err(|err| self.maybe_err_dotdotlt_syntax(maybe_lt, err))?,
@@ -709,7 +709,7 @@ impl<'a> Parser<'a> {
 
     /// Recover on `not expr` in favor of `!expr`.
     fn recover_not_expr(&mut self, lo: Span) -> PResult<'a, (Span, ExprKind)> {
-        let negated_token = self.look_ahead(1, |t| t.clone());
+        let negated_token = self.look_ahead(1, |t| *t);
 
         let sub_diag = if negated_token.is_numeric_lit() {
             errors::NotAsNegationOperatorSub::SuggestNotBitwise
@@ -1664,7 +1664,7 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_expr_path_start(&mut self) -> PResult<'a, P<Expr>> {
-        let maybe_eq_tok = self.prev_token.clone();
+        let maybe_eq_tok = self.prev_token;
         let (qself, path) = if self.eat_lt() {
             let lt_span = self.prev_token.span;
             let (qself, path) = self.parse_qpath(PathStyle::Expr).map_err(|mut err| {
@@ -2110,7 +2110,7 @@ impl<'a> Parser<'a> {
         &mut self,
         mk_lit_char: impl FnOnce(Symbol, Span) -> L,
     ) -> PResult<'a, L> {
-        let token = self.token.clone();
+        let token = self.token;
         let err = |self_: &Self| {
             let msg = format!("unexpected token: {}", super::token_descr(&token));
             self_.dcx().struct_span_err(token.span, msg)
@@ -2453,7 +2453,7 @@ impl<'a> Parser<'a> {
     fn parse_expr_closure(&mut self) -> PResult<'a, P<Expr>> {
         let lo = self.token.span;
 
-        let before = self.prev_token.clone();
+        let before = self.prev_token;
         let binder = if self.check_keyword(kw::For) {
             let lo = self.token.span;
             let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
@@ -2484,8 +2484,8 @@ impl<'a> Parser<'a> {
             FnRetTy::Default(_) => {
                 let restrictions =
                     self.restrictions - Restrictions::STMT_EXPR - Restrictions::ALLOW_LET;
-                let prev = self.prev_token.clone();
-                let token = self.token.clone();
+                let prev = self.prev_token;
+                let token = self.token;
                 match self.parse_expr_res(restrictions, None) {
                     Ok(expr) => expr,
                     Err(err) => self.recover_closure_body(err, before, prev, token, lo, decl_hi)?,
@@ -2682,7 +2682,7 @@ impl<'a> Parser<'a> {
             }
         } else {
             let attrs = self.parse_outer_attributes()?; // For recovery.
-            let maybe_fatarrow = self.token.clone();
+            let maybe_fatarrow = self.token;
             let block = if self.check(&token::OpenDelim(Delimiter::Brace)) {
                 self.parse_block()?
             } else {
@@ -3871,7 +3871,7 @@ impl<'a> Parser<'a> {
                 return Err(this.dcx().create_err(errors::ExpectedStructField {
                     span: this.look_ahead(1, |t| t.span),
                     ident_span: this.token.span,
-                    token: this.look_ahead(1, |t| t.clone()),
+                    token: this.look_ahead(1, |t| *t),
                 }));
             }
             let (ident, expr) = if is_shorthand {

compiler/rustc_parse/src/parser/item.rs

@@ -1672,8 +1672,7 @@ impl<'a> Parser<'a> {
             self.expect_semi()?;
             body
         } else {
-            let err =
-                errors::UnexpectedTokenAfterStructName::new(self.token.span, self.token.clone());
+            let err = errors::UnexpectedTokenAfterStructName::new(self.token.span, self.token);
             return Err(self.dcx().create_err(err));
         };
 
@@ -2207,7 +2206,7 @@ impl<'a> Parser<'a> {
             || self.token.is_keyword(kw::Union))
             && self.look_ahead(1, |t| t.is_ident())
         {
-            let kw_token = self.token.clone();
+            let kw_token = self.token;
             let kw_str = pprust::token_to_string(&kw_token);
             let item = self.parse_item(ForceCollect::No)?;
             self.dcx().emit_err(errors::NestedAdt {

compiler/rustc_parse/src/parser/mod.rs

@@ -310,12 +310,12 @@ impl TokenCursor {
             // below can be removed.
             if let Some(tree) = self.tree_cursor.next_ref() {
                 match tree {
-                    &TokenTree::Token(ref token, spacing) => {
+                    &TokenTree::Token(token, spacing) => {
                         debug_assert!(!matches!(
                             token.kind,
                             token::OpenDelim(_) | token::CloseDelim(_)
                         ));
-                        return (token.clone(), spacing);
+                        return (token, spacing);
                     }
                     &TokenTree::Delimited(sp, spacing, delim, ref tts) => {
                         let trees = tts.clone().into_trees();
@@ -606,7 +606,7 @@ impl<'a> Parser<'a> {
     fn check(&mut self, tok: &TokenKind) -> bool {
         let is_present = self.token == *tok;
         if !is_present {
-            self.expected_tokens.push(TokenType::Token(tok.clone()));
+            self.expected_tokens.push(TokenType::Token(*tok));
         }
         is_present
     }
@@ -1474,7 +1474,7 @@ impl<'a> Parser<'a> {
             _ => {
                 let prev_spacing = self.token_spacing;
                 self.bump();
-                TokenTree::Token(self.prev_token.clone(), prev_spacing)
+                TokenTree::Token(self.prev_token, prev_spacing)
             }
         }
     }
@@ -1657,13 +1657,14 @@ impl<'a> Parser<'a> {
                 // we don't need N spans, but we want at least one, so print all of prev_token
                 dbg_fmt.field("prev_token", &parser.prev_token);
                 // make it easier to peek farther ahead by taking TokenKinds only until EOF
-                let tokens = (0..*lookahead)
-                    .map(|i| parser.look_ahead(i, |tok| tok.kind.clone()))
-                    .scan(parser.prev_token == TokenKind::Eof, |eof, tok| {
-                        let current = eof.then_some(tok.clone()); // include a trailing EOF token
+                let tokens = (0..*lookahead).map(|i| parser.look_ahead(i, |tok| tok.kind)).scan(
+                    parser.prev_token == TokenKind::Eof,
+                    |eof, tok| {
+                        let current = eof.then_some(tok); // include a trailing EOF token
                         *eof |= &tok == &TokenKind::Eof;
                         current
-                    });
+                    },
+                );
                 dbg_fmt.field_with("tokens", |field| field.debug_list().entries(tokens).finish());
                 dbg_fmt.field("approx_token_stream_pos", &parser.num_bump_calls);