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Diffstat (limited to 'compiler/rustc_parse/src/parser/item.rs')
-rw-r--r--compiler/rustc_parse/src/parser/item.rs408
1 files changed, 225 insertions, 183 deletions
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index aad18578375..4be8a90368d 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -34,10 +34,10 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a `mod <foo> { ... }` or `mod <foo>;` item.
-    fn parse_item_mod(&mut self, attrs: &mut AttrVec) -> PResult<'a, ItemInfo> {
+    fn parse_item_mod(&mut self, attrs: &mut AttrVec) -> PResult<'a, ItemKind> {
         let safety = self.parse_safety(Case::Sensitive);
         self.expect_keyword(exp!(Mod))?;
-        let id = self.parse_ident()?;
+        let ident = self.parse_ident()?;
         let mod_kind = if self.eat(exp!(Semi)) {
             ModKind::Unloaded
         } else {
@@ -46,7 +46,7 @@ impl<'a> Parser<'a> {
             attrs.extend(inner_attrs);
             ModKind::Loaded(items, Inline::Yes, inner_span, Ok(()))
         };
-        Ok((id, ItemKind::Mod(safety, mod_kind)))
+        Ok(ItemKind::Mod(safety, ident, mod_kind))
     }
 
     /// Parses the contents of a module (inner attributes followed by module items).
@@ -115,8 +115,6 @@ impl<'a> Parser<'a> {
     }
 }
 
-pub(super) type ItemInfo = (Ident, ItemKind);
-
 impl<'a> Parser<'a> {
     pub fn parse_item(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<P<Item>>> {
         let fn_parse_mode = FnParseMode { req_name: |_| true, req_body: true };
@@ -163,11 +161,11 @@ impl<'a> Parser<'a> {
                 fn_parse_mode,
                 Case::Sensitive,
             )?;
-            if let Some((ident, kind)) = kind {
+            if let Some(kind) = kind {
                 this.error_on_unconsumed_default(def, &kind);
                 let span = lo.to(this.prev_token.span);
                 let id = DUMMY_NODE_ID;
-                let item = Item { ident, attrs, id, kind, vis, span, tokens: None };
+                let item = Item { attrs, id, kind, vis, span, tokens: None };
                 return Ok((Some(item), Trailing::No, UsePreAttrPos::No));
             }
 
@@ -208,7 +206,7 @@ impl<'a> Parser<'a> {
         def: &mut Defaultness,
         fn_parse_mode: FnParseMode,
         case: Case,
-    ) -> PResult<'a, Option<ItemInfo>> {
+    ) -> PResult<'a, Option<ItemKind>> {
         let check_pub = def == &Defaultness::Final;
         let mut def_ = || mem::replace(def, Defaultness::Final);
 
@@ -218,17 +216,15 @@ impl<'a> Parser<'a> {
             // FUNCTION ITEM
             let (ident, sig, generics, contract, body) =
                 self.parse_fn(attrs, fn_parse_mode, lo, vis, case)?;
-            (
+            ItemKind::Fn(Box::new(Fn {
+                defaultness: def_(),
                 ident,
-                ItemKind::Fn(Box::new(Fn {
-                    defaultness: def_(),
-                    sig,
-                    generics,
-                    contract,
-                    body,
-                    define_opaque: None,
-                })),
-            )
+                sig,
+                generics,
+                contract,
+                body,
+                define_opaque: None,
+            }))
         } else if self.eat_keyword(exp!(Extern)) {
             if self.eat_keyword(exp!(Crate)) {
                 // EXTERN CRATE
@@ -247,8 +243,7 @@ impl<'a> Parser<'a> {
             // STATIC ITEM
             self.bump(); // `static`
             let mutability = self.parse_mutability();
-            let (ident, item) = self.parse_static_item(safety, mutability)?;
-            (ident, ItemKind::Static(Box::new(item)))
+            self.parse_static_item(safety, mutability)?
         } else if let Const::Yes(const_span) = self.parse_constness(Case::Sensitive) {
             // CONST ITEM
             if self.token.is_keyword(kw::Impl) {
@@ -258,16 +253,14 @@ impl<'a> Parser<'a> {
                 self.recover_const_mut(const_span);
                 self.recover_missing_kw_before_item()?;
                 let (ident, generics, ty, expr) = self.parse_const_item()?;
-                (
+                ItemKind::Const(Box::new(ConstItem {
+                    defaultness: def_(),
                     ident,
-                    ItemKind::Const(Box::new(ConstItem {
-                        defaultness: def_(),
-                        generics,
-                        ty,
-                        expr,
-                        define_opaque: None,
-                    })),
-                )
+                    generics,
+                    ty,
+                    expr,
+                    define_opaque: None,
+                }))
             }
         } else if self.check_keyword(exp!(Trait)) || self.check_auto_or_unsafe_trait_item() {
             // TRAIT ITEM
@@ -334,14 +327,14 @@ impl<'a> Parser<'a> {
                 self.recover_missing_kw_before_item()?;
             }
             // MACRO INVOCATION ITEM
-            (Ident::empty(), ItemKind::MacCall(P(self.parse_item_macro(vis)?)))
+            ItemKind::MacCall(P(self.parse_item_macro(vis)?))
         } else {
             return Ok(None);
         };
         Ok(Some(info))
     }
 
-    fn recover_import_as_use(&mut self) -> PResult<'a, Option<ItemInfo>> {
+    fn recover_import_as_use(&mut self) -> PResult<'a, Option<ItemKind>> {
         let span = self.token.span;
         let token_name = super::token_descr(&self.token);
         let snapshot = self.create_snapshot_for_diagnostic();
@@ -359,7 +352,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    fn parse_use_item(&mut self) -> PResult<'a, ItemInfo> {
+    fn parse_use_item(&mut self) -> PResult<'a, ItemKind> {
         let tree = self.parse_use_tree()?;
         if let Err(mut e) = self.expect_semi() {
             match tree.kind {
@@ -373,7 +366,7 @@ impl<'a> Parser<'a> {
             }
             return Err(e);
         }
-        Ok((Ident::empty(), ItemKind::Use(tree)))
+        Ok(ItemKind::Use(tree))
     }
 
     /// When parsing a statement, would the start of a path be an item?
@@ -406,14 +399,9 @@ impl<'a> Parser<'a> {
         let insert_span = ident_span.shrink_to_lo();
 
         let ident = if self.token.is_ident()
-            && (!is_const || self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Parenthesis)))
+            && (!is_const || self.look_ahead(1, |t| *t == token::OpenParen))
             && self.look_ahead(1, |t| {
-                [
-                    token::Lt,
-                    token::OpenDelim(Delimiter::Brace),
-                    token::OpenDelim(Delimiter::Parenthesis),
-                ]
-                .contains(&t.kind)
+                matches!(t.kind, token::Lt | token::OpenBrace | token::OpenParen)
             }) {
             self.parse_ident().unwrap()
         } else {
@@ -429,7 +417,7 @@ impl<'a> Parser<'a> {
 
         let err = if self.check(exp!(OpenBrace)) {
             // possible struct or enum definition where `struct` or `enum` was forgotten
-            if self.look_ahead(1, |t| *t == token::CloseDelim(Delimiter::Brace)) {
+            if self.look_ahead(1, |t| *t == token::CloseBrace) {
                 // `S {}` could be unit enum or struct
                 Some(errors::MissingKeywordForItemDefinition::EnumOrStruct { span })
             } else if self.look_ahead(2, |t| *t == token::Colon)
@@ -483,7 +471,7 @@ impl<'a> Parser<'a> {
         if let Some(err) = err { Err(self.dcx().create_err(err)) } else { Ok(()) }
     }
 
-    fn parse_item_builtin(&mut self) -> PResult<'a, Option<ItemInfo>> {
+    fn parse_item_builtin(&mut self) -> PResult<'a, Option<ItemKind>> {
         // To be expanded
         Ok(None)
     }
@@ -577,7 +565,7 @@ impl<'a> Parser<'a> {
         &mut self,
         attrs: &mut AttrVec,
         defaultness: Defaultness,
-    ) -> PResult<'a, ItemInfo> {
+    ) -> PResult<'a, ItemKind> {
         let safety = self.parse_safety(Case::Sensitive);
         self.expect_keyword(exp!(Impl))?;
 
@@ -598,7 +586,7 @@ impl<'a> Parser<'a> {
         }
 
         // Parse stray `impl async Trait`
-        if (self.token.uninterpolated_span().at_least_rust_2018()
+        if (self.token_uninterpolated_span().at_least_rust_2018()
             && self.token.is_keyword(kw::Async))
             || self.is_kw_followed_by_ident(kw::Async)
         {
@@ -609,21 +597,13 @@ impl<'a> Parser<'a> {
         let polarity = self.parse_polarity();
 
         // Parse both types and traits as a type, then reinterpret if necessary.
-        let err_path = |span| ast::Path::from_ident(Ident::new(kw::Empty, span));
         let ty_first = if self.token.is_keyword(kw::For) && self.look_ahead(1, |t| t != &token::Lt)
         {
             let span = self.prev_token.span.between(self.token.span);
-            self.dcx().emit_err(errors::MissingTraitInTraitImpl {
+            return Err(self.dcx().create_err(errors::MissingTraitInTraitImpl {
                 span,
                 for_span: span.to(self.token.span),
-            });
-
-            P(Ty {
-                kind: TyKind::Path(None, err_path(span)),
-                span,
-                id: DUMMY_NODE_ID,
-                tokens: None,
-            })
+            }));
         } else {
             self.parse_ty_with_generics_recovery(&generics)?
         };
@@ -664,6 +644,7 @@ impl<'a> Parser<'a> {
                     other => {
                         if let TyKind::ImplTrait(_, bounds) = other
                             && let [bound] = bounds.as_slice()
+                            && let GenericBound::Trait(poly_trait_ref) = bound
                         {
                             // Suggest removing extra `impl` keyword:
                             // `impl<T: Default> impl Default for Wrapper<T>`
@@ -673,12 +654,12 @@ impl<'a> Parser<'a> {
                                 extra_impl_kw,
                                 impl_trait_span: ty_first.span,
                             });
+                            poly_trait_ref.trait_ref.path.clone()
                         } else {
-                            self.dcx().emit_err(errors::ExpectedTraitInTraitImplFoundType {
-                                span: ty_first.span,
-                            });
+                            return Err(self.dcx().create_err(
+                                errors::ExpectedTraitInTraitImplFoundType { span: ty_first.span },
+                            ));
                         }
-                        err_path(ty_first.span)
                     }
                 };
                 let trait_ref = TraitRef { path, ref_id: ty_first.id };
@@ -687,7 +668,7 @@ impl<'a> Parser<'a> {
             }
             None => (None, ty_first), // impl Type
         };
-        let item_kind = ItemKind::Impl(Box::new(Impl {
+        Ok(ItemKind::Impl(Box::new(Impl {
             safety,
             polarity,
             defaultness,
@@ -696,12 +677,10 @@ impl<'a> Parser<'a> {
             of_trait,
             self_ty,
             items: impl_items,
-        }));
-
-        Ok((Ident::empty(), item_kind))
+        })))
     }
 
-    fn parse_item_delegation(&mut self) -> PResult<'a, ItemInfo> {
+    fn parse_item_delegation(&mut self) -> PResult<'a, ItemKind> {
         let span = self.token.span;
         self.expect_keyword(exp!(Reuse))?;
 
@@ -724,7 +703,7 @@ impl<'a> Parser<'a> {
             })
         };
 
-        let (ident, item_kind) = if self.eat_path_sep() {
+        let item_kind = if self.eat_path_sep() {
             let suffixes = if self.eat(exp!(Star)) {
                 None
             } else {
@@ -732,7 +711,7 @@ impl<'a> Parser<'a> {
                 Some(self.parse_delim_comma_seq(exp!(OpenBrace), exp!(CloseBrace), parse_suffix)?.0)
             };
             let deleg = DelegationMac { qself, prefix: path, suffixes, body: body(self)? };
-            (Ident::empty(), ItemKind::DelegationMac(Box::new(deleg)))
+            ItemKind::DelegationMac(Box::new(deleg))
         } else {
             let rename = rename(self)?;
             let ident = rename.unwrap_or_else(|| path.segments.last().unwrap().ident);
@@ -740,17 +719,18 @@ impl<'a> Parser<'a> {
                 id: DUMMY_NODE_ID,
                 qself,
                 path,
+                ident,
                 rename,
                 body: body(self)?,
                 from_glob: false,
             };
-            (ident, ItemKind::Delegation(Box::new(deleg)))
+            ItemKind::Delegation(Box::new(deleg))
         };
 
         let span = span.to(self.prev_token.span);
         self.psess.gated_spans.gate(sym::fn_delegation, span);
 
-        Ok((ident, item_kind))
+        Ok(item_kind)
     }
 
     fn parse_item_list<T>(
@@ -779,11 +759,12 @@ impl<'a> Parser<'a> {
             match parse_item(self) {
                 Ok(None) => {
                     let mut is_unnecessary_semicolon = !items.is_empty()
-                        // When the close delim is `)` in a case like the following, `token.kind` is expected to be `token::CloseDelim(Delimiter::Parenthesis)`,
-                        // but the actual `token.kind` is `token::CloseDelim(Delimiter::Brace)`.
-                        // This is because the `token.kind` of the close delim is treated as the same as
-                        // that of the open delim in `TokenTreesReader::parse_token_tree`, even if the delimiters of them are different.
-                        // Therefore, `token.kind` should not be compared here.
+                        // When the close delim is `)` in a case like the following, `token.kind`
+                        // is expected to be `token::CloseParen`, but the actual `token.kind` is
+                        // `token::CloseBrace`. This is because the `token.kind` of the close delim
+                        // is treated as the same as that of the open delim in
+                        // `TokenTreesReader::parse_token_tree`, even if the delimiters of them are
+                        // different. Therefore, `token.kind` should not be compared here.
                         //
                         // issue-60075.rs
                         // ```
@@ -802,8 +783,8 @@ impl<'a> Parser<'a> {
                     let mut semicolon_span = self.token.span;
                     if !is_unnecessary_semicolon {
                         // #105369, Detect spurious `;` before assoc fn body
-                        is_unnecessary_semicolon = self.token == token::OpenDelim(Delimiter::Brace)
-                            && self.prev_token == token::Semi;
+                        is_unnecessary_semicolon =
+                            self.token == token::OpenBrace && self.prev_token == token::Semi;
                         semicolon_span = self.prev_token.span;
                     }
                     // We have to bail or we'll potentially never make progress.
@@ -855,7 +836,7 @@ impl<'a> Parser<'a> {
     /// Recover on a doc comment before `}`.
     fn recover_doc_comment_before_brace(&mut self) -> bool {
         if let token::DocComment(..) = self.token.kind {
-            if self.look_ahead(1, |tok| tok == &token::CloseDelim(Delimiter::Brace)) {
+            if self.look_ahead(1, |tok| tok == &token::CloseBrace) {
                 // FIXME: merge with `DocCommentDoesNotDocumentAnything` (E0585)
                 struct_span_code_err!(
                     self.dcx(),
@@ -885,7 +866,7 @@ impl<'a> Parser<'a> {
             && self.look_ahead(1, |t| t.is_non_raw_ident_where(|i| i.name != kw::As))
         {
             self.bump(); // `default`
-            Defaultness::Default(self.prev_token.uninterpolated_span())
+            Defaultness::Default(self.prev_token_uninterpolated_span())
         } else {
             Defaultness::Final
         }
@@ -900,7 +881,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses `unsafe? auto? trait Foo { ... }` or `trait Foo = Bar;`.
-    fn parse_item_trait(&mut self, attrs: &mut AttrVec, lo: Span) -> PResult<'a, ItemInfo> {
+    fn parse_item_trait(&mut self, attrs: &mut AttrVec, lo: Span) -> PResult<'a, ItemKind> {
         let safety = self.parse_safety(Case::Sensitive);
         // Parse optional `auto` prefix.
         let is_auto = if self.eat_keyword(exp!(Auto)) {
@@ -941,15 +922,12 @@ impl<'a> Parser<'a> {
 
             self.psess.gated_spans.gate(sym::trait_alias, whole_span);
 
-            Ok((ident, ItemKind::TraitAlias(generics, bounds)))
+            Ok(ItemKind::TraitAlias(ident, generics, bounds))
         } else {
             // It's a normal trait.
             generics.where_clause = self.parse_where_clause()?;
             let items = self.parse_item_list(attrs, |p| p.parse_trait_item(ForceCollect::No))?;
-            Ok((
-                ident,
-                ItemKind::Trait(Box::new(Trait { is_auto, safety, generics, bounds, items })),
-            ))
+            Ok(ItemKind::Trait(Box::new(Trait { is_auto, safety, ident, generics, bounds, items })))
         }
     }
 
@@ -977,11 +955,12 @@ impl<'a> Parser<'a> {
         force_collect: ForceCollect,
     ) -> PResult<'a, Option<Option<P<AssocItem>>>> {
         Ok(self.parse_item_(fn_parse_mode, force_collect)?.map(
-            |Item { attrs, id, span, vis, ident, kind, tokens }| {
+            |Item { attrs, id, span, vis, kind, tokens }| {
                 let kind = match AssocItemKind::try_from(kind) {
                     Ok(kind) => kind,
                     Err(kind) => match kind {
                         ItemKind::Static(box StaticItem {
+                            ident,
                             ty,
                             safety: _,
                             mutability: _,
@@ -991,6 +970,7 @@ impl<'a> Parser<'a> {
                             self.dcx().emit_err(errors::AssociatedStaticItemNotAllowed { span });
                             AssocItemKind::Const(Box::new(ConstItem {
                                 defaultness: Defaultness::Final,
+                                ident,
                                 generics: Generics::default(),
                                 ty,
                                 expr,
@@ -1000,7 +980,7 @@ impl<'a> Parser<'a> {
                         _ => return self.error_bad_item_kind(span, &kind, "`trait`s or `impl`s"),
                     },
                 };
-                Some(P(Item { attrs, id, span, vis, ident, kind, tokens }))
+                Some(P(Item { attrs, id, span, vis, kind, tokens }))
             },
         ))
     }
@@ -1010,7 +990,7 @@ impl<'a> Parser<'a> {
     /// TypeAlias = "type" Ident Generics (":" GenericBounds)? WhereClause ("=" Ty)? WhereClause ";" ;
     /// ```
     /// The `"type"` has already been eaten.
-    fn parse_type_alias(&mut self, defaultness: Defaultness) -> PResult<'a, ItemInfo> {
+    fn parse_type_alias(&mut self, defaultness: Defaultness) -> PResult<'a, ItemKind> {
         let ident = self.parse_ident()?;
         let mut generics = self.parse_generics()?;
 
@@ -1045,16 +1025,14 @@ impl<'a> Parser<'a> {
 
         self.expect_semi()?;
 
-        Ok((
+        Ok(ItemKind::TyAlias(Box::new(TyAlias {
+            defaultness,
             ident,
-            ItemKind::TyAlias(Box::new(TyAlias {
-                defaultness,
-                generics,
-                where_clauses,
-                bounds,
-                ty,
-            })),
-        ))
+            generics,
+            where_clauses,
+            bounds,
+            ty,
+        })))
     }
 
     /// Parses a `UseTree`.
@@ -1158,16 +1136,16 @@ impl<'a> Parser<'a> {
     /// extern crate foo;
     /// extern crate bar as foo;
     /// ```
-    fn parse_item_extern_crate(&mut self) -> PResult<'a, ItemInfo> {
+    fn parse_item_extern_crate(&mut self) -> PResult<'a, ItemKind> {
         // Accept `extern crate name-like-this` for better diagnostics
-        let orig_name = self.parse_crate_name_with_dashes()?;
-        let (item_name, orig_name) = if let Some(rename) = self.parse_rename()? {
-            (rename, Some(orig_name.name))
+        let orig_ident = self.parse_crate_name_with_dashes()?;
+        let (orig_name, item_ident) = if let Some(rename) = self.parse_rename()? {
+            (Some(orig_ident.name), rename)
         } else {
-            (orig_name, None)
+            (None, orig_ident)
         };
         self.expect_semi()?;
-        Ok((item_name, ItemKind::ExternCrate(orig_name)))
+        Ok(ItemKind::ExternCrate(orig_name, item_ident))
     }
 
     fn parse_crate_name_with_dashes(&mut self) -> PResult<'a, Ident> {
@@ -1218,25 +1196,24 @@ impl<'a> Parser<'a> {
         &mut self,
         attrs: &mut AttrVec,
         mut safety: Safety,
-    ) -> PResult<'a, ItemInfo> {
-        let extern_span = self.prev_token.uninterpolated_span();
+    ) -> PResult<'a, ItemKind> {
+        let extern_span = self.prev_token_uninterpolated_span();
         let abi = self.parse_abi(); // ABI?
         // FIXME: This recovery should be tested better.
         if safety == Safety::Default
             && self.token.is_keyword(kw::Unsafe)
-            && self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Brace))
+            && self.look_ahead(1, |t| *t == token::OpenBrace)
         {
             self.expect(exp!(OpenBrace)).unwrap_err().emit();
             safety = Safety::Unsafe(self.token.span);
             let _ = self.eat_keyword(exp!(Unsafe));
         }
-        let module = ast::ForeignMod {
+        Ok(ItemKind::ForeignMod(ast::ForeignMod {
             extern_span,
             safety,
             abi,
             items: self.parse_item_list(attrs, |p| p.parse_foreign_item(ForceCollect::No))?,
-        };
-        Ok((Ident::empty(), ItemKind::ForeignMod(module)))
+        }))
     }
 
     /// Parses a foreign item (one in an `extern { ... }` block).
@@ -1246,11 +1223,11 @@ impl<'a> Parser<'a> {
     ) -> PResult<'a, Option<Option<P<ForeignItem>>>> {
         let fn_parse_mode = FnParseMode { req_name: |_| true, req_body: false };
         Ok(self.parse_item_(fn_parse_mode, force_collect)?.map(
-            |Item { attrs, id, span, vis, ident, kind, tokens }| {
+            |Item { attrs, id, span, vis, kind, tokens }| {
                 let kind = match ForeignItemKind::try_from(kind) {
                     Ok(kind) => kind,
                     Err(kind) => match kind {
-                        ItemKind::Const(box ConstItem { ty, expr, .. }) => {
+                        ItemKind::Const(box ConstItem { ident, ty, expr, .. }) => {
                             let const_span = Some(span.with_hi(ident.span.lo()))
                                 .filter(|span| span.can_be_used_for_suggestions());
                             self.dcx().emit_err(errors::ExternItemCannotBeConst {
@@ -1258,6 +1235,7 @@ impl<'a> Parser<'a> {
                                 const_span,
                             });
                             ForeignItemKind::Static(Box::new(StaticItem {
+                                ident,
                                 ty,
                                 mutability: Mutability::Not,
                                 expr,
@@ -1268,7 +1246,7 @@ impl<'a> Parser<'a> {
                         _ => return self.error_bad_item_kind(span, &kind, "`extern` blocks"),
                     },
                 };
-                Some(P(Item { attrs, id, span, vis, ident, kind, tokens }))
+                Some(P(Item { attrs, id, span, vis, kind, tokens }))
             },
         ))
     }
@@ -1301,12 +1279,24 @@ impl<'a> Parser<'a> {
     }
 
     fn is_unsafe_foreign_mod(&self) -> bool {
-        self.token.is_keyword(kw::Unsafe)
-            && self.is_keyword_ahead(1, &[kw::Extern])
-            && self.look_ahead(
-                2 + self.look_ahead(2, |t| t.can_begin_string_literal() as usize),
-                |t| *t == token::OpenDelim(Delimiter::Brace),
-            )
+        // Look for `unsafe`.
+        if !self.token.is_keyword(kw::Unsafe) {
+            return false;
+        }
+        // Look for `extern`.
+        if !self.is_keyword_ahead(1, &[kw::Extern]) {
+            return false;
+        }
+
+        // Look for the optional ABI string literal.
+        let n = if self.look_ahead(2, |t| t.can_begin_string_literal()) { 3 } else { 2 };
+
+        // Look for the `{`. Use `tree_look_ahead` because the ABI (if present)
+        // might be a metavariable i.e. an invisible-delimited sequence, and
+        // `tree_look_ahead` will consider that a single element when looking
+        // ahead.
+        self.tree_look_ahead(n, |t| matches!(t, TokenTree::Delimited(_, _, Delimiter::Brace, _)))
+            == Some(true)
     }
 
     fn is_static_global(&mut self) -> bool {
@@ -1343,13 +1333,13 @@ impl<'a> Parser<'a> {
         const_span: Span,
         attrs: &mut AttrVec,
         defaultness: Defaultness,
-    ) -> PResult<'a, ItemInfo> {
+    ) -> PResult<'a, ItemKind> {
         let impl_span = self.token.span;
         let err = self.expected_ident_found_err();
 
         // Only try to recover if this is implementing a trait for a type
-        let mut impl_info = match self.parse_item_impl(attrs, defaultness) {
-            Ok(impl_info) => impl_info,
+        let mut item_kind = match self.parse_item_impl(attrs, defaultness) {
+            Ok(item_kind) => item_kind,
             Err(recovery_error) => {
                 // Recovery failed, raise the "expected identifier" error
                 recovery_error.cancel();
@@ -1357,7 +1347,7 @@ impl<'a> Parser<'a> {
             }
         };
 
-        match &mut impl_info.1 {
+        match &mut item_kind {
             ItemKind::Impl(box Impl { of_trait: Some(trai), constness, .. }) => {
                 *constness = Const::Yes(const_span);
 
@@ -1374,10 +1364,11 @@ impl<'a> Parser<'a> {
             _ => unreachable!(),
         }
 
-        Ok(impl_info)
+        Ok(item_kind)
     }
 
-    /// Parse a static item with the prefix `"static" "mut"?` already parsed and stored in `mutability`.
+    /// Parse a static item with the prefix `"static" "mut"?` already parsed and stored in
+    /// `mutability`.
     ///
     /// ```ebnf
     /// Static = "static" "mut"? $ident ":" $ty (= $expr)? ";" ;
@@ -1386,7 +1377,7 @@ impl<'a> Parser<'a> {
         &mut self,
         safety: Safety,
         mutability: Mutability,
-    ) -> PResult<'a, (Ident, StaticItem)> {
+    ) -> PResult<'a, ItemKind> {
         let ident = self.parse_ident()?;
 
         if self.token == TokenKind::Lt && self.may_recover() {
@@ -1398,7 +1389,8 @@ impl<'a> Parser<'a> {
         // FIXME: This could maybe benefit from `.may_recover()`?
         let ty = match (self.eat(exp!(Colon)), self.check(exp!(Eq)) | self.check(exp!(Semi))) {
             (true, false) => self.parse_ty()?,
-            // If there wasn't a `:` or the colon was followed by a `=` or `;`, recover a missing type.
+            // If there wasn't a `:` or the colon was followed by a `=` or `;`, recover a missing
+            // type.
             (colon, _) => self.recover_missing_global_item_type(colon, Some(mutability)),
         };
 
@@ -1406,7 +1398,8 @@ impl<'a> Parser<'a> {
 
         self.expect_semi()?;
 
-        Ok((ident, StaticItem { ty, safety, mutability, expr, define_opaque: None }))
+        let item = StaticItem { ident, ty, safety, mutability, expr, define_opaque: None };
+        Ok(ItemKind::Static(Box::new(item)))
     }
 
     /// Parse a constant item with the prefix `"const"` already parsed.
@@ -1531,7 +1524,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses an enum declaration.
-    fn parse_item_enum(&mut self) -> PResult<'a, ItemInfo> {
+    fn parse_item_enum(&mut self) -> PResult<'a, ItemKind> {
         if self.token.is_keyword(kw::Struct) {
             let span = self.prev_token.span.to(self.token.span);
             let err = errors::EnumStructMutuallyExclusive { span };
@@ -1544,7 +1537,7 @@ impl<'a> Parser<'a> {
         }
 
         let prev_span = self.prev_token.span;
-        let id = self.parse_ident()?;
+        let ident = self.parse_ident()?;
         let mut generics = self.parse_generics()?;
         generics.where_clause = self.parse_where_clause()?;
 
@@ -1555,10 +1548,10 @@ impl<'a> Parser<'a> {
             (thin_vec![], Trailing::No)
         } else {
             self.parse_delim_comma_seq(exp!(OpenBrace), exp!(CloseBrace), |p| {
-                p.parse_enum_variant(id.span)
+                p.parse_enum_variant(ident.span)
             })
             .map_err(|mut err| {
-                err.span_label(id.span, "while parsing this enum");
+                err.span_label(ident.span, "while parsing this enum");
                 if self.token == token::Colon {
                     let snapshot = self.create_snapshot_for_diagnostic();
                     self.bump();
@@ -1584,7 +1577,7 @@ impl<'a> Parser<'a> {
         };
 
         let enum_definition = EnumDef { variants: variants.into_iter().flatten().collect() };
-        Ok((id, ItemKind::Enum(enum_definition, generics)))
+        Ok(ItemKind::Enum(ident, enum_definition, generics))
     }
 
     fn parse_enum_variant(&mut self, span: Span) -> PResult<'a, Option<Variant>> {
@@ -1676,8 +1669,8 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses `struct Foo { ... }`.
-    fn parse_item_struct(&mut self) -> PResult<'a, ItemInfo> {
-        let class_name = self.parse_ident()?;
+    fn parse_item_struct(&mut self) -> PResult<'a, ItemKind> {
+        let ident = self.parse_ident()?;
 
         let mut generics = self.parse_generics()?;
 
@@ -1698,7 +1691,7 @@ impl<'a> Parser<'a> {
         let vdata = if self.token.is_keyword(kw::Where) {
             let tuple_struct_body;
             (generics.where_clause, tuple_struct_body) =
-                self.parse_struct_where_clause(class_name, generics.span)?;
+                self.parse_struct_where_clause(ident, generics.span)?;
 
             if let Some(body) = tuple_struct_body {
                 // If we see a misplaced tuple struct body: `struct Foo<T> where T: Copy, (T);`
@@ -1712,7 +1705,7 @@ impl<'a> Parser<'a> {
                 // If we see: `struct Foo<T> where T: Copy { ... }`
                 let (fields, recovered) = self.parse_record_struct_body(
                     "struct",
-                    class_name.span,
+                    ident.span,
                     generics.where_clause.has_where_token,
                 )?;
                 VariantData::Struct { fields, recovered }
@@ -1721,31 +1714,30 @@ impl<'a> Parser<'a> {
         } else if self.eat(exp!(Semi)) {
             VariantData::Unit(DUMMY_NODE_ID)
         // Record-style struct definition
-        } else if self.token == token::OpenDelim(Delimiter::Brace) {
+        } else if self.token == token::OpenBrace {
             let (fields, recovered) = self.parse_record_struct_body(
                 "struct",
-                class_name.span,
+                ident.span,
                 generics.where_clause.has_where_token,
             )?;
             VariantData::Struct { fields, recovered }
         // Tuple-style struct definition with optional where-clause.
-        } else if self.token == token::OpenDelim(Delimiter::Parenthesis) {
+        } else if self.token == token::OpenParen {
             let body = VariantData::Tuple(self.parse_tuple_struct_body()?, DUMMY_NODE_ID);
             generics.where_clause = self.parse_where_clause()?;
             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));
         };
 
-        Ok((class_name, ItemKind::Struct(vdata, generics)))
+        Ok(ItemKind::Struct(ident, vdata, generics))
     }
 
     /// Parses `union Foo { ... }`.
-    fn parse_item_union(&mut self) -> PResult<'a, ItemInfo> {
-        let class_name = self.parse_ident()?;
+    fn parse_item_union(&mut self) -> PResult<'a, ItemKind> {
+        let ident = self.parse_ident()?;
 
         let mut generics = self.parse_generics()?;
 
@@ -1753,14 +1745,14 @@ impl<'a> Parser<'a> {
             generics.where_clause = self.parse_where_clause()?;
             let (fields, recovered) = self.parse_record_struct_body(
                 "union",
-                class_name.span,
+                ident.span,
                 generics.where_clause.has_where_token,
             )?;
             VariantData::Struct { fields, recovered }
-        } else if self.token == token::OpenDelim(Delimiter::Brace) {
+        } else if self.token == token::OpenBrace {
             let (fields, recovered) = self.parse_record_struct_body(
                 "union",
-                class_name.span,
+                ident.span,
                 generics.where_clause.has_where_token,
             )?;
             VariantData::Struct { fields, recovered }
@@ -1772,7 +1764,7 @@ impl<'a> Parser<'a> {
             return Err(err);
         };
 
-        Ok((class_name, ItemKind::Union(vdata, generics)))
+        Ok(ItemKind::Union(ident, vdata, generics))
     }
 
     /// This function parses the fields of record structs:
@@ -1788,7 +1780,7 @@ impl<'a> Parser<'a> {
         let mut fields = ThinVec::new();
         let mut recovered = Recovered::No;
         if self.eat(exp!(OpenBrace)) {
-            while self.token != token::CloseDelim(Delimiter::Brace) {
+            while self.token != token::CloseBrace {
                 match self.parse_field_def(adt_ty) {
                     Ok(field) => {
                         fields.push(field);
@@ -1945,7 +1937,7 @@ impl<'a> Parser<'a> {
             token::Comma => {
                 self.bump();
             }
-            token::CloseDelim(Delimiter::Brace) => {}
+            token::CloseBrace => {}
             token::DocComment(..) => {
                 let previous_span = self.prev_token.span;
                 let mut err = errors::DocCommentDoesNotDocumentAnything {
@@ -1959,7 +1951,7 @@ impl<'a> Parser<'a> {
                 if !seen_comma && comma_after_doc_seen {
                     seen_comma = true;
                 }
-                if comma_after_doc_seen || self.token == token::CloseDelim(Delimiter::Brace) {
+                if comma_after_doc_seen || self.token == token::CloseBrace {
                     self.dcx().emit_err(err);
                 } else {
                     if !seen_comma {
@@ -1997,7 +1989,7 @@ impl<'a> Parser<'a> {
 
                 if self.token.is_ident()
                     || (self.token == TokenKind::Pound
-                        && (self.look_ahead(1, |t| t == &token::OpenDelim(Delimiter::Bracket))))
+                        && (self.look_ahead(1, |t| t == &token::OpenBracket)))
                 {
                     // This is likely another field, TokenKind::Pound is used for `#[..]`
                     // attribute for next field. Emit the diagnostic and continue parsing.
@@ -2066,6 +2058,17 @@ impl<'a> Parser<'a> {
         }
         self.expect_field_ty_separator()?;
         let ty = self.parse_ty()?;
+        if self.token == token::Colon && self.look_ahead(1, |&t| t != token::Colon) {
+            self.dcx()
+                .struct_span_err(self.token.span, "found single colon in a struct field type path")
+                .with_span_suggestion_verbose(
+                    self.token.span,
+                    "write a path separator here",
+                    "::",
+                    Applicability::MaybeIncorrect,
+                )
+                .emit();
+        }
         let default = if self.token == token::Eq {
             self.bump();
             let const_expr = self.parse_expr_anon_const()?;
@@ -2124,15 +2127,17 @@ impl<'a> Parser<'a> {
                 }
             } else if self.eat_keyword(exp!(Struct)) {
                 match self.parse_item_struct() {
-                    Ok((ident, _)) => self
-                        .dcx()
-                        .struct_span_err(
-                            lo.with_hi(ident.span.hi()),
-                            format!("structs are not allowed in {adt_ty} definitions"),
-                        )
-                        .with_help(
-                            "consider creating a new `struct` definition instead of nesting",
-                        ),
+                    Ok(item) => {
+                        let ItemKind::Struct(ident, ..) = item else { unreachable!() };
+                        self.dcx()
+                            .struct_span_err(
+                                lo.with_hi(ident.span.hi()),
+                                format!("structs are not allowed in {adt_ty} definitions"),
+                            )
+                            .with_help(
+                                "consider creating a new `struct` definition instead of nesting",
+                            )
+                    }
                     Err(err) => {
                         err.cancel();
                         self.restore_snapshot(snapshot);
@@ -2177,7 +2182,7 @@ impl<'a> Parser<'a> {
     /// MacParams = "(" TOKEN_STREAM ")" ;
     /// DeclMac = "macro" Ident MacParams? MacBody ;
     /// ```
-    fn parse_item_decl_macro(&mut self, lo: Span) -> PResult<'a, ItemInfo> {
+    fn parse_item_decl_macro(&mut self, lo: Span) -> PResult<'a, ItemKind> {
         let ident = self.parse_ident()?;
         let body = if self.check(exp!(OpenBrace)) {
             self.parse_delim_args()? // `MacBody`
@@ -2199,7 +2204,7 @@ impl<'a> Parser<'a> {
         };
 
         self.psess.gated_spans.gate(sym::decl_macro, lo.to(self.prev_token.span));
-        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, macro_rules: false })))
+        Ok(ItemKind::MacroDef(ident, ast::MacroDef { body, macro_rules: false }))
     }
 
     /// Is this a possibly malformed start of a `macro_rules! foo` item definition?
@@ -2228,7 +2233,7 @@ impl<'a> Parser<'a> {
         &mut self,
         vis: &Visibility,
         has_bang: bool,
-    ) -> PResult<'a, ItemInfo> {
+    ) -> PResult<'a, ItemKind> {
         self.expect_keyword(exp!(MacroRules))?; // `macro_rules`
 
         if has_bang {
@@ -2246,7 +2251,7 @@ impl<'a> Parser<'a> {
         self.eat_semi_for_macro_if_needed(&body);
         self.complain_if_pub_macro(vis, true);
 
-        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, macro_rules: true })))
+        Ok(ItemKind::MacroDef(ident, ast::MacroDef { body, macro_rules: true }))
     }
 
     /// Item macro invocations or `macro_rules!` definitions need inherited visibility.
@@ -2304,7 +2309,7 @@ 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)?;
             let mut item = item.unwrap().span;
@@ -2449,7 +2454,7 @@ impl<'a> Parser<'a> {
         match self.expected_one_of_not_found(&[], expected) {
             Ok(error_guaranteed) => Ok(error_guaranteed),
             Err(mut err) => {
-                if self.token == token::CloseDelim(Delimiter::Brace) {
+                if self.token == token::CloseBrace {
                     // The enclosing `mod`, `trait` or `impl` is being closed, so keep the `fn` in
                     // the AST for typechecking.
                     err.span_label(ident_span, "while parsing this `fn`");
@@ -2537,7 +2542,7 @@ impl<'a> Parser<'a> {
             self.expect_semi()?;
             *sig_hi = self.prev_token.span;
             (AttrVec::new(), None)
-        } else if self.check(exp!(OpenBrace)) || self.token.is_whole_block() {
+        } else if self.check(exp!(OpenBrace)) || self.token.is_metavar_block() {
             self.parse_block_common(self.token.span, BlockCheckMode::Default, None)
                 .map(|(attrs, body)| (attrs, Some(body)))?
         } else if self.token == token::Eq {
@@ -2610,13 +2615,36 @@ impl<'a> Parser<'a> {
                 })
             // `extern ABI fn`
             || self.check_keyword_case(exp!(Extern), case)
+                // Use `tree_look_ahead` because `ABI` might be a metavariable,
+                // i.e. an invisible-delimited sequence, and `tree_look_ahead`
+                // will consider that a single element when looking ahead.
                 && self.look_ahead(1, |t| t.can_begin_string_literal())
-                && (self.look_ahead(2, |t| t.is_keyword_case(kw::Fn, case)) ||
+                && (self.tree_look_ahead(2, |tt| {
+                    match tt {
+                        TokenTree::Token(t, _) => t.is_keyword_case(kw::Fn, case),
+                        TokenTree::Delimited(..) => false,
+                    }
+                }) == Some(true) ||
                     // This branch is only for better diagnostics; `pub`, `unsafe`, etc. are not
                     // allowed here.
                     (self.may_recover()
-                        && self.look_ahead(2, |t| ALL_QUALS.iter().any(|exp| t.is_keyword(exp.kw)))
-                        && self.look_ahead(3, |t| t.is_keyword_case(kw::Fn, case))))
+                        && self.tree_look_ahead(2, |tt| {
+                            match tt {
+                                TokenTree::Token(t, _) =>
+                                    ALL_QUALS.iter().any(|exp| {
+                                        t.is_keyword(exp.kw)
+                                    }),
+                                TokenTree::Delimited(..) => false,
+                            }
+                        }) == Some(true)
+                        && self.tree_look_ahead(3, |tt| {
+                            match tt {
+                                TokenTree::Token(t, _) => t.is_keyword_case(kw::Fn, case),
+                                TokenTree::Delimited(..) => false,
+                            }
+                        }) == Some(true)
+                    )
+                )
     }
 
     /// Parses all the "front matter" (or "qualifiers") for a `fn` declaration,
@@ -2752,7 +2780,7 @@ impl<'a> Parser<'a> {
                             .expect("Span extracted directly from keyword should always work");
 
                         err.span_suggestion(
-                            self.token.uninterpolated_span(),
+                            self.token_uninterpolated_span(),
                             format!("`{original_kw}` already used earlier, remove this one"),
                             "",
                             Applicability::MachineApplicable,
@@ -2763,7 +2791,7 @@ impl<'a> Parser<'a> {
                     else if let Some(WrongKw::Misplaced(correct_pos_sp)) = wrong_kw {
                         let correct_pos_sp = correct_pos_sp.to(self.prev_token.span);
                         if let Ok(current_qual) = self.span_to_snippet(correct_pos_sp) {
-                            let misplaced_qual_sp = self.token.uninterpolated_span();
+                            let misplaced_qual_sp = self.token_uninterpolated_span();
                             let misplaced_qual = self.span_to_snippet(misplaced_qual_sp).unwrap();
 
                             err.span_suggestion(
@@ -2853,7 +2881,7 @@ impl<'a> Parser<'a> {
     pub(super) fn parse_fn_params(&mut self, req_name: ReqName) -> PResult<'a, ThinVec<Param>> {
         let mut first_param = true;
         // Parse the arguments, starting out with `self` being allowed...
-        if self.token != TokenKind::OpenDelim(Delimiter::Parenthesis)
+        if self.token != TokenKind::OpenParen
         // might be typo'd trait impl, handled elsewhere
         && !self.token.is_keyword(kw::For)
         {
@@ -2871,7 +2899,7 @@ impl<'a> Parser<'a> {
                 // When parsing a param failed, we should check to make the span of the param
                 // not contain '(' before it.
                 // For example when parsing `*mut Self` in function `fn oof(*mut Self)`.
-                let lo = if let TokenKind::OpenDelim(Delimiter::Parenthesis) = p.prev_token.kind {
+                let lo = if let TokenKind::OpenParen = p.prev_token.kind {
                     p.prev_token.span.shrink_to_hi()
                 } else {
                     p.prev_token.span
@@ -2931,23 +2959,37 @@ impl<'a> Parser<'a> {
                 let parser_snapshot_before_ty = this.create_snapshot_for_diagnostic();
                 this.eat_incorrect_doc_comment_for_param_type();
                 let mut ty = this.parse_ty_for_param();
-                if ty.is_ok()
-                    && this.token != token::Comma
-                    && this.token != token::CloseDelim(Delimiter::Parenthesis)
-                {
-                    // This wasn't actually a type, but a pattern looking like a type,
-                    // so we are going to rollback and re-parse for recovery.
-                    ty = this.unexpected_any();
+
+                if let Ok(t) = &ty {
+                    // Check for trailing angle brackets
+                    if let TyKind::Path(_, Path { segments, .. }) = &t.kind {
+                        if let Some(segment) = segments.last() {
+                            if let Some(guar) =
+                                this.check_trailing_angle_brackets(segment, &[exp!(CloseParen)])
+                            {
+                                return Ok((
+                                    dummy_arg(segment.ident, guar),
+                                    Trailing::No,
+                                    UsePreAttrPos::No,
+                                ));
+                            }
+                        }
+                    }
+
+                    if this.token != token::Comma && this.token != token::CloseParen {
+                        // This wasn't actually a type, but a pattern looking like a type,
+                        // so we are going to rollback and re-parse for recovery.
+                        ty = this.unexpected_any();
+                    }
                 }
                 match ty {
                     Ok(ty) => {
-                        let ident = Ident::new(kw::Empty, this.prev_token.span);
-                        let bm = BindingMode::NONE;
-                        let pat = this.mk_pat_ident(ty.span, bm, ident);
+                        let pat = this.mk_pat(ty.span, PatKind::Missing);
                         (pat, ty)
                     }
                     // If this is a C-variadic argument and we hit an error, return the error.
                     Err(err) if this.token == token::DotDotDot => return Err(err),
+                    Err(err) if this.unmatched_angle_bracket_count > 0 => return Err(err),
                     // Recover from attempting to parse the argument as a type without pattern.
                     Err(err) => {
                         err.cancel();
@@ -3116,7 +3158,7 @@ impl<'a> Parser<'a> {
 
     fn is_named_param(&self) -> bool {
         let offset = match &self.token.kind {
-            token::OpenDelim(Delimiter::Invisible(origin)) => match origin {
+            token::OpenInvisible(origin) => match origin {
                 InvisibleOrigin::MetaVar(MetaVarKind::Pat(_)) => {
                     return self.check_noexpect_past_close_delim(&token::Colon);
                 }