`rustc_expand`: remove `ref` patterns

8 files changed, 75 insertions, 82 deletions

diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index ffde8480c02..951d5924678 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -63,21 +63,21 @@ pub enum Annotatable {
 
 impl Annotatable {
     pub fn span(&self) -> Span {
-        match *self {
-            Annotatable::Item(ref item) => item.span,
-            Annotatable::TraitItem(ref trait_item) => trait_item.span,
-            Annotatable::ImplItem(ref impl_item) => impl_item.span,
-            Annotatable::ForeignItem(ref foreign_item) => foreign_item.span,
-            Annotatable::Stmt(ref stmt) => stmt.span,
-            Annotatable::Expr(ref expr) => expr.span,
-            Annotatable::Arm(ref arm) => arm.span,
-            Annotatable::ExprField(ref field) => field.span,
-            Annotatable::PatField(ref fp) => fp.pat.span,
-            Annotatable::GenericParam(ref gp) => gp.ident.span,
-            Annotatable::Param(ref p) => p.span,
-            Annotatable::FieldDef(ref sf) => sf.span,
-            Annotatable::Variant(ref v) => v.span,
-            Annotatable::Crate(ref c) => c.spans.inner_span,
+        match self {
+            Annotatable::Item(item) => item.span,
+            Annotatable::TraitItem(trait_item) => trait_item.span,
+            Annotatable::ImplItem(impl_item) => impl_item.span,
+            Annotatable::ForeignItem(foreign_item) => foreign_item.span,
+            Annotatable::Stmt(stmt) => stmt.span,
+            Annotatable::Expr(expr) => expr.span,
+            Annotatable::Arm(arm) => arm.span,
+            Annotatable::ExprField(field) => field.span,
+            Annotatable::PatField(fp) => fp.pat.span,
+            Annotatable::GenericParam(gp) => gp.ident.span,
+            Annotatable::Param(p) => p.span,
+            Annotatable::FieldDef(sf) => sf.span,
+            Annotatable::Variant(v) => v.span,
+            Annotatable::Crate(c) => c.spans.inner_span,
         }
     }
 
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index f4c6f3386ad..1fcbdfd9be5 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -298,7 +298,7 @@ impl<'a> StripUnconfigured<'a> {
                     Some(AttrTokenTree::Delimited(sp, delim, inner))
                         .into_iter()
                 }
-                AttrTokenTree::Token(ref token, _) if let TokenKind::Interpolated(ref nt) = token.kind => {
+                AttrTokenTree::Token(ref token, _) if let TokenKind::Interpolated(nt) = &token.kind => {
                     panic!(
                         "Nonterminal should have been flattened at {:?}: {:?}",
                         token.span, nt
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index 5d47c1ed363..79d058d9c97 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -144,12 +144,12 @@ macro_rules! ast_fragments {
             }
 
             pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
-                match *self {
-                    AstFragment::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
+                match self {
+                    AstFragment::OptExpr(Some(expr)) => visitor.visit_expr(expr),
                     AstFragment::OptExpr(None) => {}
-                    AstFragment::MethodReceiverExpr(ref expr) => visitor.visit_method_receiver_expr(expr),
-                    $($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)?)*
-                    $($(AstFragment::$Kind(ref ast) => for ast_elt in &ast[..] {
+                    AstFragment::MethodReceiverExpr(expr) => visitor.visit_method_receiver_expr(expr),
+                    $($(AstFragment::$Kind(ast) => visitor.$visit_ast(ast),)?)*
+                    $($(AstFragment::$Kind(ast) => for ast_elt in &ast[..] {
                         visitor.$visit_ast_elt(ast_elt, $($args)*);
                     })?)*
                 }
@@ -592,7 +592,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                     let expn_id = invoc.expansion_data.id;
                     let parent_def = self.cx.resolver.invocation_parent(expn_id);
                     let span = match &mut invoc.kind {
-                        InvocationKind::Bang { ref mut span, .. } => span,
+                        InvocationKind::Bang { span, .. } => span,
                         InvocationKind::Attr { attr, .. } => &mut attr.span,
                         InvocationKind::Derive { path, .. } => &mut path.span,
                     };
@@ -945,8 +945,8 @@ pub fn ensure_complete_parse<'a>(
         let def_site_span = parser.token.span.with_ctxt(SyntaxContext::root());
 
         let semi_span = parser.sess.source_map().next_point(span);
-        let add_semicolon = match parser.sess.source_map().span_to_snippet(semi_span) {
-            Ok(ref snippet) if &snippet[..] != ";" && kind_name == "expression" => {
+        let add_semicolon = match &parser.sess.source_map().span_to_snippet(semi_span) {
+            Ok(snippet) if &snippet[..] != ";" && kind_name == "expression" => {
                 Some(span.shrink_to_hi())
             }
             _ => None,
diff --git a/compiler/rustc_expand/src/mbe/macro_check.rs b/compiler/rustc_expand/src/mbe/macro_check.rs
index 0b8847f827d..5be134f4e66 100644
--- a/compiler/rustc_expand/src/mbe/macro_check.rs
+++ b/compiler/rustc_expand/src/mbe/macro_check.rs
@@ -151,9 +151,9 @@ impl<'a, T> Iterator for &'a Stack<'a, T> {
 
     // Iterates from top to bottom of the stack.
     fn next(&mut self) -> Option<&'a T> {
-        match *self {
+        match self {
             Stack::Empty => None,
-            Stack::Push { ref top, ref prev } => {
+            Stack::Push { top, prev } => {
                 *self = prev;
                 Some(top)
             }
@@ -437,8 +437,8 @@ fn check_nested_occurrences(
                 // We check that the meta-variable is correctly used.
                 check_occurrences(sess, node_id, tt, macros, binders, ops, valid);
             }
-            (NestedMacroState::MacroRulesNotName, &TokenTree::Delimited(_, ref del))
-            | (NestedMacroState::MacroName, &TokenTree::Delimited(_, ref del))
+            (NestedMacroState::MacroRulesNotName, TokenTree::Delimited(_, del))
+            | (NestedMacroState::MacroName, TokenTree::Delimited(_, del))
                 if del.delim == Delimiter::Brace =>
             {
                 let macro_rules = state == NestedMacroState::MacroRulesNotName;
@@ -497,7 +497,7 @@ fn check_nested_occurrences(
                     valid,
                 );
             }
-            (_, ref tt) => {
+            (_, tt) => {
                 state = NestedMacroState::Empty;
                 check_occurrences(sess, node_id, tt, macros, binders, ops, valid);
             }
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index c0489f68633..4ebd75f0185 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -486,11 +486,11 @@ pub fn compile_declarative_macro(
     let mut valid = true;
 
     // Extract the arguments:
-    let lhses = match argument_map[&MacroRulesNormalizedIdent::new(lhs_nm)] {
-        MatchedSeq(ref s) => s
+    let lhses = match &argument_map[&MacroRulesNormalizedIdent::new(lhs_nm)] {
+        MatchedSeq(s) => s
             .iter()
             .map(|m| {
-                if let MatchedTokenTree(ref tt) = *m {
+                if let MatchedTokenTree(tt) = m {
                     let tt = mbe::quoted::parse(
                         TokenStream::new(vec![tt.clone()]),
                         true,
@@ -510,11 +510,11 @@ pub fn compile_declarative_macro(
         _ => sess.parse_sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs"),
     };
 
-    let rhses = match argument_map[&MacroRulesNormalizedIdent::new(rhs_nm)] {
-        MatchedSeq(ref s) => s
+    let rhses = match &argument_map[&MacroRulesNormalizedIdent::new(rhs_nm)] {
+        MatchedSeq(s) => s
             .iter()
             .map(|m| {
-                if let MatchedTokenTree(ref tt) = *m {
+                if let MatchedTokenTree(tt) = m {
                     return mbe::quoted::parse(
                         TokenStream::new(vec![tt.clone()]),
                         false,
@@ -624,21 +624,21 @@ fn check_lhs_nt_follows(sess: &ParseSess, def: &ast::Item, lhs: &mbe::TokenTree)
 fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[mbe::TokenTree]) -> bool {
     use mbe::TokenTree;
     for tt in tts {
-        match *tt {
+        match tt {
             TokenTree::Token(..)
             | TokenTree::MetaVar(..)
             | TokenTree::MetaVarDecl(..)
             | TokenTree::MetaVarExpr(..) => (),
-            TokenTree::Delimited(_, ref del) => {
+            TokenTree::Delimited(_, del) => {
                 if !check_lhs_no_empty_seq(sess, &del.tts) {
                     return false;
                 }
             }
-            TokenTree::Sequence(span, ref seq) => {
+            TokenTree::Sequence(span, seq) => {
                 if seq.separator.is_none()
-                    && seq.tts.iter().all(|seq_tt| match *seq_tt {
+                    && seq.tts.iter().all(|seq_tt| match seq_tt {
                         TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Vis)) => true,
-                        TokenTree::Sequence(_, ref sub_seq) => {
+                        TokenTree::Sequence(_, sub_seq) => {
                             sub_seq.kleene.op == mbe::KleeneOp::ZeroOrMore
                                 || sub_seq.kleene.op == mbe::KleeneOp::ZeroOrOne
                         }
@@ -736,21 +736,21 @@ impl<'tt> FirstSets<'tt> {
         fn build_recur<'tt>(sets: &mut FirstSets<'tt>, tts: &'tt [TokenTree]) -> TokenSet<'tt> {
             let mut first = TokenSet::empty();
             for tt in tts.iter().rev() {
-                match *tt {
+                match tt {
                     TokenTree::Token(..)
                     | TokenTree::MetaVar(..)
                     | TokenTree::MetaVarDecl(..)
                     | TokenTree::MetaVarExpr(..) => {
                         first.replace_with(TtHandle::TtRef(tt));
                     }
-                    TokenTree::Delimited(span, ref delimited) => {
+                    TokenTree::Delimited(span, delimited) => {
                         build_recur(sets, &delimited.tts);
                         first.replace_with(TtHandle::from_token_kind(
                             token::OpenDelim(delimited.delim),
                             span.open,
                         ));
                     }
-                    TokenTree::Sequence(sp, ref seq_rep) => {
+                    TokenTree::Sequence(sp, seq_rep) => {
                         let subfirst = build_recur(sets, &seq_rep.tts);
 
                         match sets.first.entry(sp.entire()) {
@@ -804,7 +804,7 @@ impl<'tt> FirstSets<'tt> {
         let mut first = TokenSet::empty();
         for tt in tts.iter() {
             assert!(first.maybe_empty);
-            match *tt {
+            match tt {
                 TokenTree::Token(..)
                 | TokenTree::MetaVar(..)
                 | TokenTree::MetaVarDecl(..)
@@ -812,14 +812,14 @@ impl<'tt> FirstSets<'tt> {
                     first.add_one(TtHandle::TtRef(tt));
                     return first;
                 }
-                TokenTree::Delimited(span, ref delimited) => {
+                TokenTree::Delimited(span, delimited) => {
                     first.add_one(TtHandle::from_token_kind(
                         token::OpenDelim(delimited.delim),
                         span.open,
                     ));
                     return first;
                 }
-                TokenTree::Sequence(sp, ref seq_rep) => {
+                TokenTree::Sequence(sp, seq_rep) => {
                     let subfirst_owned;
                     let subfirst = match self.first.get(&sp.entire()) {
                         Some(Some(subfirst)) => subfirst,
@@ -1041,7 +1041,7 @@ fn check_matcher_core<'tt>(
 
         // First, update `last` so that it corresponds to the set
         // of NT tokens that might end the sequence `... token`.
-        match *token {
+        match token {
             TokenTree::Token(..)
             | TokenTree::MetaVar(..)
             | TokenTree::MetaVarDecl(..)
@@ -1057,7 +1057,7 @@ fn check_matcher_core<'tt>(
                     suffix_first = build_suffix_first();
                 }
             }
-            TokenTree::Delimited(span, ref d) => {
+            TokenTree::Delimited(span, d) => {
                 let my_suffix = TokenSet::singleton(TtHandle::from_token_kind(
                     token::CloseDelim(d.delim),
                     span.close,
@@ -1070,7 +1070,7 @@ fn check_matcher_core<'tt>(
                 // against SUFFIX
                 continue 'each_token;
             }
-            TokenTree::Sequence(_, ref seq_rep) => {
+            TokenTree::Sequence(_, seq_rep) => {
                 suffix_first = build_suffix_first();
                 // The trick here: when we check the interior, we want
                 // to include the separator (if any) as a potential
@@ -1372,8 +1372,8 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow {
 }
 
 fn quoted_tt_to_string(tt: &mbe::TokenTree) -> String {
-    match *tt {
-        mbe::TokenTree::Token(ref token) => pprust::token_to_string(&token).into(),
+    match tt {
+        mbe::TokenTree::Token(token) => pprust::token_to_string(&token).into(),
         mbe::TokenTree::MetaVar(_, name) => format!("${}", name),
         mbe::TokenTree::MetaVarDecl(_, name, Some(kind)) => format!("${}:{}", name, kind),
         mbe::TokenTree::MetaVarDecl(_, name, None) => format!("${}:", name),
diff --git a/compiler/rustc_expand/src/mbe/transcribe.rs b/compiler/rustc_expand/src/mbe/transcribe.rs
index bec6d1a2df7..b79835be73a 100644
--- a/compiler/rustc_expand/src/mbe/transcribe.rs
+++ b/compiler/rustc_expand/src/mbe/transcribe.rs
@@ -47,8 +47,7 @@ impl<'a> Iterator for Frame<'a> {
 
     fn next(&mut self) -> Option<&'a mbe::TokenTree> {
         match self {
-            Frame::Delimited { tts, ref mut idx, .. }
-            | Frame::Sequence { tts, ref mut idx, .. } => {
+            Frame::Delimited { tts, idx, .. } | Frame::Sequence { tts, idx, .. } => {
                 let res = tts.get(*idx);
                 *idx += 1;
                 res
@@ -220,13 +219,13 @@ pub(super) fn transcribe<'a>(
                 let ident = MacroRulesNormalizedIdent::new(original_ident);
                 if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) {
                     match cur_matched {
-                        MatchedTokenTree(ref tt) => {
+                        MatchedTokenTree(tt) => {
                             // `tt`s are emitted into the output stream directly as "raw tokens",
                             // without wrapping them into groups.
                             let token = tt.clone();
                             result.push(token);
                         }
-                        MatchedNonterminal(ref nt) => {
+                        MatchedNonterminal(nt) => {
                             // Other variables are emitted into the output stream as groups with
                             // `Delimiter::Invisible` to maintain parsing priorities.
                             // `Interpolated` is currently used for such groups in rustc parser.
@@ -299,12 +298,11 @@ fn lookup_cur_matched<'a>(
     interpolations: &'a FxHashMap<MacroRulesNormalizedIdent, NamedMatch>,
     repeats: &[(usize, usize)],
 ) -> Option<&'a NamedMatch> {
-    interpolations.get(&ident).map(|matched| {
-        let mut matched = matched;
+    interpolations.get(&ident).map(|mut matched| {
         for &(idx, _) in repeats {
             match matched {
                 MatchedTokenTree(_) | MatchedNonterminal(_) => break,
-                MatchedSeq(ref ads) => matched = ads.get(idx).unwrap(),
+                MatchedSeq(ads) => matched = ads.get(idx).unwrap(),
             }
         }
 
@@ -339,7 +337,7 @@ impl LockstepIterSize {
         match self {
             LockstepIterSize::Unconstrained => other,
             LockstepIterSize::Contradiction(_) => self,
-            LockstepIterSize::Constraint(l_len, ref l_id) => match other {
+            LockstepIterSize::Constraint(l_len, l_id) => match other {
                 LockstepIterSize::Unconstrained => self,
                 LockstepIterSize::Contradiction(_) => other,
                 LockstepIterSize::Constraint(r_len, _) if l_len == r_len => self,
@@ -378,33 +376,33 @@ fn lockstep_iter_size(
     repeats: &[(usize, usize)],
 ) -> LockstepIterSize {
     use mbe::TokenTree;
-    match *tree {
-        TokenTree::Delimited(_, ref delimited) => {
+    match tree {
+        TokenTree::Delimited(_, delimited) => {
             delimited.tts.iter().fold(LockstepIterSize::Unconstrained, |size, tt| {
                 size.with(lockstep_iter_size(tt, interpolations, repeats))
             })
         }
-        TokenTree::Sequence(_, ref seq) => {
+        TokenTree::Sequence(_, seq) => {
             seq.tts.iter().fold(LockstepIterSize::Unconstrained, |size, tt| {
                 size.with(lockstep_iter_size(tt, interpolations, repeats))
             })
         }
         TokenTree::MetaVar(_, name) | TokenTree::MetaVarDecl(_, name, _) => {
-            let name = MacroRulesNormalizedIdent::new(name);
+            let name = MacroRulesNormalizedIdent::new(*name);
             match lookup_cur_matched(name, interpolations, repeats) {
                 Some(matched) => match matched {
                     MatchedTokenTree(_) | MatchedNonterminal(_) => LockstepIterSize::Unconstrained,
-                    MatchedSeq(ref ads) => LockstepIterSize::Constraint(ads.len(), name),
+                    MatchedSeq(ads) => LockstepIterSize::Constraint(ads.len(), name),
                 },
                 _ => LockstepIterSize::Unconstrained,
             }
         }
-        TokenTree::MetaVarExpr(_, ref expr) => {
+        TokenTree::MetaVarExpr(_, expr) => {
             let default_rslt = LockstepIterSize::Unconstrained;
             let Some(ident) = expr.ident() else { return default_rslt; };
             let name = MacroRulesNormalizedIdent::new(ident);
             match lookup_cur_matched(name, interpolations, repeats) {
-                Some(MatchedSeq(ref ads)) => {
+                Some(MatchedSeq(ads)) => {
                     default_rslt.with(LockstepIterSize::Constraint(ads.len(), name))
                 }
                 _ => default_rslt,
@@ -449,7 +447,7 @@ fn count_repetitions<'a>(
                     Some(_) => Err(out_of_bounds_err(cx, declared_lhs_depth, sp.entire(), "count")),
                 }
             }
-            MatchedSeq(ref named_matches) => {
+            MatchedSeq(named_matches) => {
                 let new_declared_lhs_depth = declared_lhs_depth + 1;
                 match depth_opt {
                     None => named_matches
@@ -472,7 +470,7 @@ fn count_repetitions<'a>(
     // before we start counting. `matched` contains the various levels of the
     // tree as we descend, and its final value is the subtree we are currently at.
     for &(idx, _) in repeats {
-        if let MatchedSeq(ref ads) = matched {
+        if let MatchedSeq(ads) = matched {
             matched = &ads[idx];
         }
     }
diff --git a/compiler/rustc_expand/src/parse/tests.rs b/compiler/rustc_expand/src/parse/tests.rs
index e49f112bf20..0726d922c84 100644
--- a/compiler/rustc_expand/src/parse/tests.rs
+++ b/compiler/rustc_expand/src/parse/tests.rs
@@ -176,9 +176,9 @@ fn get_spans_of_pat_idents(src: &str) -> Vec<Span> {
     }
     impl<'a> visit::Visitor<'a> for PatIdentVisitor {
         fn visit_pat(&mut self, p: &'a ast::Pat) {
-            match p.kind {
-                PatKind::Ident(_, ref ident, _) => {
-                    self.spans.push(ident.span.clone());
+            match &p.kind {
+                PatKind::Ident(_, ident, _) => {
+                    self.spans.push(ident.span);
                 }
                 _ => {
                     visit::walk_pat(self, p);
@@ -290,10 +290,8 @@ fn ttdelim_span() {
         )
         .unwrap();
 
-        let tts: Vec<_> = match expr.kind {
-            ast::ExprKind::MacCall(ref mac) => mac.args.tokens.clone().into_trees().collect(),
-            _ => panic!("not a macro"),
-        };
+        let ast::ExprKind::MacCall(mac) = &expr.kind else { panic!("not a macro") };
+        let tts: Vec<_> = mac.args.tokens.clone().into_trees().collect();
 
         let span = tts.iter().rev().next().unwrap().span();
 
@@ -318,11 +316,8 @@ fn out_of_line_mod() {
         .unwrap()
         .unwrap();
 
-        if let ast::ItemKind::Mod(_, ref mod_kind) = item.kind {
-            assert!(matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2));
-        } else {
-            panic!();
-        }
+        let ast::ItemKind::Mod(_, mod_kind) = &item.kind else { panic!() };
+        assert!(matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2));
     });
 }
 
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 768bdab8a54..df59c1132cc 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -597,8 +597,8 @@ impl server::SourceFile for Rustc<'_, '_> {
     }
 
     fn path(&mut self, file: &Self::SourceFile) -> String {
-        match file.name {
-            FileName::Real(ref name) => name
+        match &file.name {
+            FileName::Real(name) => name
                 .local_path()
                 .expect("attempting to get a file path in an imported file in `proc_macro::SourceFile::path`")
                 .to_str()