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-rw-r--r--compiler/rustc_parse/src/errors.rs7
-rw-r--r--compiler/rustc_parse/src/parser/attr.rs51
-rw-r--r--compiler/rustc_parse/src/parser/expr.rs64
-rw-r--r--compiler/rustc_parse/src/parser/generics.rs2
-rw-r--r--compiler/rustc_parse/src/parser/item.rs26
-rw-r--r--compiler/rustc_parse/src/parser/mod.rs50
-rw-r--r--compiler/rustc_parse/src/parser/nonterminal.rs15
-rw-r--r--compiler/rustc_parse/src/parser/pat.rs22
-rw-r--r--compiler/rustc_parse/src/parser/path.rs2
-rw-r--r--compiler/rustc_parse/src/parser/stmt.rs20
-rw-r--r--compiler/rustc_parse/src/parser/ty.rs2
11 files changed, 147 insertions, 114 deletions
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 32b56bb7e87..5cad3a568ee 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -851,13 +851,6 @@ pub(crate) struct StructLiteralNotAllowedHereSugg {
 }
 
 #[derive(Diagnostic)]
-#[diag(parse_invalid_interpolated_expression)]
-pub(crate) struct InvalidInterpolatedExpression {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
 #[diag(parse_invalid_literal_suffix_on_tuple_index)]
 pub(crate) struct InvalidLiteralSuffixOnTupleIndex {
     #[primary_span]
diff --git a/compiler/rustc_parse/src/parser/attr.rs b/compiler/rustc_parse/src/parser/attr.rs
index eb9a10f4bda..ab5f51eedc3 100644
--- a/compiler/rustc_parse/src/parser/attr.rs
+++ b/compiler/rustc_parse/src/parser/attr.rs
@@ -3,11 +3,12 @@ use crate::errors::{
     SuffixedLiteralInAttribute,
 };
 use crate::fluent_generated as fluent;
+use crate::maybe_whole;
 
 use super::{AttrWrapper, Capturing, FnParseMode, ForceCollect, Parser, PathStyle};
 use rustc_ast as ast;
 use rustc_ast::attr;
-use rustc_ast::token::{self, Delimiter, Nonterminal};
+use rustc_ast::token::{self, Delimiter};
 use rustc_errors::{codes::*, Diag, PResult};
 use rustc_span::{sym, BytePos, Span};
 use thin_vec::ThinVec;
@@ -251,25 +252,15 @@ impl<'a> Parser<'a> {
     ///     PATH `=` UNSUFFIXED_LIT
     /// The delimiters or `=` are still put into the resulting token stream.
     pub fn parse_attr_item(&mut self, capture_tokens: bool) -> PResult<'a, ast::AttrItem> {
-        let item = match &self.token.kind {
-            token::Interpolated(nt) => match &nt.0 {
-                Nonterminal::NtMeta(item) => Some(item.clone().into_inner()),
-                _ => None,
-            },
-            _ => None,
+        maybe_whole!(self, NtMeta, |attr| attr.into_inner());
+
+        let do_parse = |this: &mut Self| {
+            let path = this.parse_path(PathStyle::Mod)?;
+            let args = this.parse_attr_args()?;
+            Ok(ast::AttrItem { path, args, tokens: None })
         };
-        Ok(if let Some(item) = item {
-            self.bump();
-            item
-        } else {
-            let do_parse = |this: &mut Self| {
-                let path = this.parse_path(PathStyle::Mod)?;
-                let args = this.parse_attr_args()?;
-                Ok(ast::AttrItem { path, args, tokens: None })
-            };
-            // Attr items don't have attributes
-            if capture_tokens { self.collect_tokens_no_attrs(do_parse) } else { do_parse(self) }?
-        })
+        // Attr items don't have attributes
+        if capture_tokens { self.collect_tokens_no_attrs(do_parse) } else { do_parse(self) }
     }
 
     /// Parses attributes that appear after the opening of an item. These should
@@ -371,22 +362,18 @@ impl<'a> Parser<'a> {
     /// meta_item_inner : (meta_item | UNSUFFIXED_LIT) (',' meta_item_inner)? ;
     /// ```
     pub fn parse_meta_item(&mut self) -> PResult<'a, ast::MetaItem> {
-        let nt_meta = match &self.token.kind {
-            token::Interpolated(nt) => match &nt.0 {
-                token::NtMeta(e) => Some(e.clone()),
-                _ => None,
-            },
-            _ => None,
-        };
-
-        if let Some(item) = nt_meta {
-            return match item.meta(item.path.span) {
+        // We can't use `maybe_whole` here because it would bump in the `None`
+        // case, which we don't want.
+        if let token::Interpolated(nt) = &self.token.kind
+            && let token::NtMeta(attr_item) = &nt.0
+        {
+            match attr_item.meta(attr_item.path.span) {
                 Some(meta) => {
                     self.bump();
-                    Ok(meta)
+                    return Ok(meta);
                 }
-                None => self.unexpected(),
-            };
+                None => self.unexpected()?,
+            }
         }
 
         let lo = self.token.span;
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index e27a5f93799..fe17eba0d7b 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -11,7 +11,7 @@ use crate::errors;
 use crate::maybe_recover_from_interpolated_ty_qpath;
 use ast::mut_visit::{noop_visit_expr, MutVisitor};
 use ast::token::IdentIsRaw;
-use ast::{CoroutineKind, ForLoopKind, GenBlockKind, Pat, Path, PathSegment};
+use ast::{CoroutineKind, ForLoopKind, GenBlockKind, MatchKind, Pat, Path, PathSegment};
 use core::mem;
 use core::ops::ControlFlow;
 use rustc_ast::ptr::P;
@@ -943,7 +943,10 @@ impl<'a> Parser<'a> {
         // Stitch the list of outer attributes onto the return value.
         // A little bit ugly, but the best way given the current code
         // structure
-        let res = self.parse_expr_dot_or_call_with_(e0, lo);
+        let res = ensure_sufficient_stack(
+            // this expr demonstrates the recursion it guards against
+            || self.parse_expr_dot_or_call_with_(e0, lo),
+        );
         if attrs.is_empty() {
             res
         } else {
@@ -1376,6 +1379,13 @@ impl<'a> Parser<'a> {
             return Ok(self.mk_await_expr(self_arg, lo));
         }
 
+        // Post-fix match
+        if self.eat_keyword(kw::Match) {
+            let match_span = self.prev_token.span;
+            self.psess.gated_spans.gate(sym::postfix_match, match_span);
+            return self.parse_match_block(lo, match_span, self_arg, MatchKind::Postfix);
+        }
+
         let fn_span_lo = self.token.span;
         let mut seg = self.parse_path_segment(PathStyle::Expr, None)?;
         self.check_trailing_angle_brackets(&seg, &[&token::OpenDelim(Delimiter::Parenthesis)]);
@@ -1936,11 +1946,11 @@ impl<'a> Parser<'a> {
     /// Parse `builtin # ident(args,*)`.
     fn parse_expr_builtin(&mut self) -> PResult<'a, P<Expr>> {
         self.parse_builtin(|this, lo, ident| {
-            if ident.name == sym::offset_of {
-                return Ok(Some(this.parse_expr_offset_of(lo)?));
-            }
-
-            Ok(None)
+            Ok(match ident.name {
+                sym::offset_of => Some(this.parse_expr_offset_of(lo)?),
+                sym::type_ascribe => Some(this.parse_expr_type_ascribe(lo)?),
+                _ => None,
+            })
         })
     }
 
@@ -1975,6 +1985,7 @@ impl<'a> Parser<'a> {
         ret
     }
 
+    /// Built-in macro for `offset_of!` expressions.
     pub(crate) fn parse_expr_offset_of(&mut self, lo: Span) -> PResult<'a, P<Expr>> {
         let container = self.parse_ty()?;
         self.expect(&TokenKind::Comma)?;
@@ -2004,6 +2015,15 @@ impl<'a> Parser<'a> {
         Ok(self.mk_expr(span, ExprKind::OffsetOf(container, fields)))
     }
 
+    /// Built-in macro for type ascription expressions.
+    pub(crate) fn parse_expr_type_ascribe(&mut self, lo: Span) -> PResult<'a, P<Expr>> {
+        let expr = self.parse_expr()?;
+        self.expect(&token::Comma)?;
+        let ty = self.parse_ty()?;
+        let span = lo.to(self.token.span);
+        Ok(self.mk_expr(span, ExprKind::Type(expr, ty)))
+    }
+
     /// Returns a string literal if the next token is a string literal.
     /// In case of error returns `Some(lit)` if the next token is a literal with a wrong kind,
     /// and returns `None` if the next token is not literal at all.
@@ -2040,16 +2060,6 @@ impl<'a> Parser<'a> {
         &mut self,
         mk_lit_char: impl FnOnce(Symbol, Span) -> L,
     ) -> PResult<'a, L> {
-        if let token::Interpolated(nt) = &self.token.kind
-            && let token::NtExpr(e) | token::NtLiteral(e) = &nt.0
-            && matches!(e.kind, ExprKind::Err(_))
-        {
-            let mut err = self
-                .dcx()
-                .create_err(errors::InvalidInterpolatedExpression { span: self.token.span });
-            err.downgrade_to_delayed_bug();
-            return Err(err);
-        }
         let token = self.token.clone();
         let err = |self_: &Self| {
             let msg = format!("unexpected token: {}", super::token_descr(&token));
@@ -2891,8 +2901,20 @@ impl<'a> Parser<'a> {
     /// Parses a `match ... { ... }` expression (`match` token already eaten).
     fn parse_expr_match(&mut self) -> PResult<'a, P<Expr>> {
         let match_span = self.prev_token.span;
-        let lo = self.prev_token.span;
         let scrutinee = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?;
+
+        self.parse_match_block(match_span, match_span, scrutinee, MatchKind::Prefix)
+    }
+
+    /// Parses the block of a `match expr { ... }` or a `expr.match { ... }`
+    /// expression. This is after the match token and scrutinee are eaten
+    fn parse_match_block(
+        &mut self,
+        lo: Span,
+        match_span: Span,
+        scrutinee: P<Expr>,
+        match_kind: MatchKind,
+    ) -> PResult<'a, P<Expr>> {
         if let Err(mut e) = self.expect(&token::OpenDelim(Delimiter::Brace)) {
             if self.token == token::Semi {
                 e.span_suggestion_short(
@@ -2935,7 +2957,7 @@ impl<'a> Parser<'a> {
                     });
                     return Ok(self.mk_expr_with_attrs(
                         span,
-                        ExprKind::Match(scrutinee, arms),
+                        ExprKind::Match(scrutinee, arms, match_kind),
                         attrs,
                     ));
                 }
@@ -2943,7 +2965,7 @@ impl<'a> Parser<'a> {
         }
         let hi = self.token.span;
         self.bump();
-        Ok(self.mk_expr_with_attrs(lo.to(hi), ExprKind::Match(scrutinee, arms), attrs))
+        Ok(self.mk_expr_with_attrs(lo.to(hi), ExprKind::Match(scrutinee, arms, match_kind), attrs))
     }
 
     /// Attempt to recover from match arm body with statements and no surrounding braces.
@@ -3952,7 +3974,7 @@ impl MutVisitor for CondChecker<'_> {
             | ExprKind::While(_, _, _)
             | ExprKind::ForLoop { .. }
             | ExprKind::Loop(_, _, _)
-            | ExprKind::Match(_, _)
+            | ExprKind::Match(_, _, _)
             | ExprKind::Closure(_)
             | ExprKind::Block(_, _)
             | ExprKind::Gen(_, _, _)
diff --git a/compiler/rustc_parse/src/parser/generics.rs b/compiler/rustc_parse/src/parser/generics.rs
index 263b2a90643..fde16ac957d 100644
--- a/compiler/rustc_parse/src/parser/generics.rs
+++ b/compiler/rustc_parse/src/parser/generics.rs
@@ -481,7 +481,7 @@ impl<'a> Parser<'a> {
             }))
         } else {
             self.maybe_recover_bounds_doubled_colon(&ty)?;
-            self.unexpected()
+            self.unexpected_any()
         }
     }
 
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 79492fe62ed..d54eb8dc4c9 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -6,6 +6,7 @@ use super::{
 };
 use crate::errors::{self, MacroExpandsToAdtField};
 use crate::fluent_generated as fluent;
+use crate::maybe_whole;
 use ast::token::IdentIsRaw;
 use rustc_ast::ast::*;
 use rustc_ast::ptr::P;
@@ -115,17 +116,10 @@ impl<'a> Parser<'a> {
         fn_parse_mode: FnParseMode,
         force_collect: ForceCollect,
     ) -> PResult<'a, Option<Item>> {
-        // Don't use `maybe_whole` so that we have precise control
-        // over when we bump the parser
-        if let token::Interpolated(nt) = &self.token.kind
-            && let token::NtItem(item) = &nt.0
-        {
-            let mut item = item.clone();
-            self.bump();
-
+        maybe_whole!(self, NtItem, |item| {
             attrs.prepend_to_nt_inner(&mut item.attrs);
-            return Ok(Some(item.into_inner()));
-        };
+            Some(item.into_inner())
+        });
 
         let item =
             self.collect_tokens_trailing_token(attrs, force_collect, |this: &mut Self, attrs| {
@@ -1514,7 +1508,7 @@ impl<'a> Parser<'a> {
                 let ident = this.parse_field_ident("enum", vlo)?;
 
                 if this.token == token::Not {
-                    if let Err(err) = this.unexpected::<()>() {
+                    if let Err(err) = this.unexpected() {
                         err.with_note(fluent::parse_macro_expands_to_enum_variant).emit();
                     }
 
@@ -1937,7 +1931,7 @@ impl<'a> Parser<'a> {
     ) -> PResult<'a, FieldDef> {
         let name = self.parse_field_ident(adt_ty, lo)?;
         if self.token.kind == token::Not {
-            if let Err(mut err) = self.unexpected::<FieldDef>() {
+            if let Err(mut err) = self.unexpected() {
                 // Encounter the macro invocation
                 err.subdiagnostic(self.dcx(), MacroExpandsToAdtField { adt_ty });
                 return Err(err);
@@ -2067,7 +2061,7 @@ impl<'a> Parser<'a> {
             let params = self.parse_token_tree(); // `MacParams`
             let pspan = params.span();
             if !self.check(&token::OpenDelim(Delimiter::Brace)) {
-                return self.unexpected();
+                self.unexpected()?;
             }
             let body = self.parse_token_tree(); // `MacBody`
             // Convert `MacParams MacBody` into `{ MacParams => MacBody }`.
@@ -2077,7 +2071,7 @@ impl<'a> Parser<'a> {
             let dspan = DelimSpan::from_pair(pspan.shrink_to_lo(), bspan.shrink_to_hi());
             P(DelimArgs { dspan, delim: Delimiter::Brace, tokens })
         } else {
-            return self.unexpected();
+            self.unexpected_any()?
         };
 
         self.psess.gated_spans.gate(sym::decl_macro, lo.to(self.prev_token.span));
@@ -2692,7 +2686,7 @@ impl<'a> Parser<'a> {
                 debug!("parse_param_general parse_pat (is_name_required:{})", is_name_required);
                 let (pat, colon) = this.parse_fn_param_pat_colon()?;
                 if !colon {
-                    let mut err = this.unexpected::<()>().unwrap_err();
+                    let mut err = this.unexpected().unwrap_err();
                     return if let Some(ident) =
                         this.parameter_without_type(&mut err, pat, is_name_required, first_param)
                     {
@@ -2716,7 +2710,7 @@ impl<'a> Parser<'a> {
                 {
                     // 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();
+                    ty = this.unexpected_any();
                 }
                 match ty {
                     Ok(ty) => {
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 13023d6fbbd..de83528b52c 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -20,7 +20,7 @@ pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma};
 pub use path::PathStyle;
 
 use rustc_ast::ptr::P;
-use rustc_ast::token::{self, Delimiter, Nonterminal, Token, TokenKind};
+use rustc_ast::token::{self, Delimiter, Token, TokenKind};
 use rustc_ast::tokenstream::{AttributesData, DelimSpacing, DelimSpan, Spacing};
 use rustc_ast::tokenstream::{TokenStream, TokenTree, TokenTreeCursor};
 use rustc_ast::util::case::Case;
@@ -93,12 +93,13 @@ pub enum TrailingToken {
 #[macro_export]
 macro_rules! maybe_whole {
     ($p:expr, $constructor:ident, |$x:ident| $e:expr) => {
-        if let token::Interpolated(nt) = &$p.token.kind {
-            if let token::$constructor(x) = &nt.0 {
-                let $x = x.clone();
-                $p.bump();
-                return Ok($e);
-            }
+        if let token::Interpolated(nt) = &$p.token.kind
+            && let token::$constructor(x) = &nt.0
+        {
+            #[allow(unused_mut)]
+            let mut $x = x.clone();
+            $p.bump();
+            return Ok($e);
         }
     };
 }
@@ -467,7 +468,9 @@ impl<'a> Parser<'a> {
         matches!(self.recovery, Recovery::Allowed)
     }
 
-    pub fn unexpected<T>(&mut self) -> PResult<'a, T> {
+    /// Version of [`unexpected`](Parser::unexpected) that "returns" any type in the `Ok`
+    /// (both those functions never return "Ok", and so can lie like that in the type).
+    pub fn unexpected_any<T>(&mut self) -> PResult<'a, T> {
         match self.expect_one_of(&[], &[]) {
             Err(e) => Err(e),
             // We can get `Ok(true)` from `recover_closing_delimiter`
@@ -476,6 +479,10 @@ impl<'a> Parser<'a> {
         }
     }
 
+    pub fn unexpected(&mut self) -> PResult<'a, ()> {
+        self.unexpected_any()
+    }
+
     /// Expects and consumes the token `t`. Signals an error if the next token is not `t`.
     pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, Recovered> {
         if self.expected_tokens.is_empty() {
@@ -1291,7 +1298,11 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_delim_args(&mut self) -> PResult<'a, P<DelimArgs>> {
-        if let Some(args) = self.parse_delim_args_inner() { Ok(P(args)) } else { self.unexpected() }
+        if let Some(args) = self.parse_delim_args_inner() {
+            Ok(P(args))
+        } else {
+            self.unexpected_any()
+        }
     }
 
     fn parse_attr_args(&mut self) -> PResult<'a, AttrArgs> {
@@ -1397,7 +1408,7 @@ impl<'a> Parser<'a> {
     /// so emit a proper diagnostic.
     // Public for rustfmt usage.
     pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> {
-        maybe_whole!(self, NtVis, |x| x.into_inner());
+        maybe_whole!(self, NtVis, |vis| vis.into_inner());
 
         if !self.eat_keyword(kw::Pub) {
             // We need a span for our `Spanned<VisibilityKind>`, but there's inherently no
@@ -1574,8 +1585,21 @@ pub enum FlatToken {
     Empty,
 }
 
-#[derive(Debug)]
-pub enum ParseNtResult {
-    Nt(Nonterminal),
+// Metavar captures of various kinds.
+#[derive(Clone, Debug)]
+pub enum ParseNtResult<NtType> {
     Tt(TokenTree),
+    Nt(NtType),
+}
+
+impl<T> ParseNtResult<T> {
+    pub fn map_nt<F, U>(self, mut f: F) -> ParseNtResult<U>
+    where
+        F: FnMut(T) -> U,
+    {
+        match self {
+            ParseNtResult::Tt(tt) => ParseNtResult::Tt(tt),
+            ParseNtResult::Nt(nt) => ParseNtResult::Nt(f(nt)),
+        }
+    }
 }
diff --git a/compiler/rustc_parse/src/parser/nonterminal.rs b/compiler/rustc_parse/src/parser/nonterminal.rs
index f1572a18a8b..36a00df7b44 100644
--- a/compiler/rustc_parse/src/parser/nonterminal.rs
+++ b/compiler/rustc_parse/src/parser/nonterminal.rs
@@ -1,5 +1,5 @@
 use rustc_ast::ptr::P;
-use rustc_ast::token::{self, Delimiter, Nonterminal::*, NonterminalKind, Token};
+use rustc_ast::token::{self, Delimiter, Nonterminal, Nonterminal::*, NonterminalKind, Token};
 use rustc_ast::HasTokens;
 use rustc_ast_pretty::pprust;
 use rustc_errors::PResult;
@@ -66,15 +66,14 @@ impl<'a> Parser<'a> {
                 token::Interpolated(nt) => may_be_ident(&nt.0),
                 _ => false,
             },
-            NonterminalKind::PatParam { .. } | NonterminalKind::PatWithOr => {
-                match &token.kind {
+            NonterminalKind::PatParam { .. } | NonterminalKind::PatWithOr => match &token.kind {
                 token::Ident(..) |                          // box, ref, mut, and other identifiers (can stricten)
                 token::OpenDelim(Delimiter::Parenthesis) |  // tuple pattern
                 token::OpenDelim(Delimiter::Bracket) |      // slice pattern
                 token::BinOp(token::And) |                  // reference
                 token::BinOp(token::Minus) |                // negative literal
                 token::AndAnd |                             // double reference
-                token::Literal(_) |                        // literal
+                token::Literal(_) |                         // literal
                 token::DotDot |                             // range pattern (future compat)
                 token::DotDotDot |                          // range pattern (future compat)
                 token::ModSep |                             // path
@@ -84,8 +83,7 @@ impl<'a> Parser<'a> {
                 token::BinOp(token::Or) => matches!(kind, NonterminalKind::PatWithOr),
                 token::Interpolated(nt) => may_be_ident(&nt.0),
                 _ => false,
-            }
-            }
+            },
             NonterminalKind::Lifetime => match &token.kind {
                 token::Lifetime(_) => true,
                 token::Interpolated(nt) => {
@@ -102,7 +100,10 @@ impl<'a> Parser<'a> {
     /// Parse a non-terminal (e.g. MBE `:pat` or `:ident`). Inlined because there is only one call
     /// site.
     #[inline]
-    pub fn parse_nonterminal(&mut self, kind: NonterminalKind) -> PResult<'a, ParseNtResult> {
+    pub fn parse_nonterminal(
+        &mut self,
+        kind: NonterminalKind,
+    ) -> PResult<'a, ParseNtResult<Nonterminal>> {
         // A `macro_rules!` invocation may pass a captured item/expr to a proc-macro,
         // which requires having captured tokens available. Since we cannot determine
         // in advance whether or not a proc-macro will be (transitively) invoked,
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index 88ae1b5420f..fbc28859535 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -435,7 +435,7 @@ impl<'a> Parser<'a> {
         syntax_loc: Option<PatternLocation>,
     ) -> PResult<'a, P<Pat>> {
         maybe_recover_from_interpolated_ty_qpath!(self, true);
-        maybe_whole!(self, NtPat, |x| x);
+        maybe_whole!(self, NtPat, |pat| pat);
 
         let mut lo = self.token.span;
 
@@ -498,11 +498,14 @@ impl<'a> Parser<'a> {
             } else {
                 PatKind::Lit(const_expr)
             }
+        } else if self.is_builtin() {
+            self.parse_pat_builtin()?
+        }
         // Don't eagerly error on semantically invalid tokens when matching
         // declarative macros, as the input to those doesn't have to be
         // semantically valid. For attribute/derive proc macros this is not the
         // case, so doing the recovery for them is fine.
-        } else if self.can_be_ident_pat()
+        else if self.can_be_ident_pat()
             || (self.is_lit_bad_ident().is_some() && self.may_recover())
         {
             // Parse `ident @ pat`
@@ -1119,6 +1122,21 @@ impl<'a> Parser<'a> {
         .contains(&self.token.kind)
     }
 
+    fn parse_pat_builtin(&mut self) -> PResult<'a, PatKind> {
+        self.parse_builtin(|self_, _lo, ident| {
+            Ok(match ident.name {
+                // builtin#deref(PAT)
+                sym::deref => Some(ast::PatKind::Deref(self_.parse_pat_allow_top_alt(
+                    None,
+                    RecoverComma::Yes,
+                    RecoverColon::Yes,
+                    CommaRecoveryMode::LikelyTuple,
+                )?)),
+                _ => None,
+            })
+        })
+    }
+
     /// Parses `box pat`
     fn parse_pat_box(&mut self) -> PResult<'a, PatKind> {
         let box_span = self.prev_token.span;
diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs
index a9fcc134c13..9153f2b9d06 100644
--- a/compiler/rustc_parse/src/parser/path.rs
+++ b/compiler/rustc_parse/src/parser/path.rs
@@ -660,7 +660,7 @@ impl<'a> Parser<'a> {
                     // Add `>` to the list of expected tokens.
                     self.check(&token::Gt);
                     // Handle `,` to `;` substitution
-                    let mut err = self.unexpected::<()>().unwrap_err();
+                    let mut err = self.unexpected().unwrap_err();
                     self.bump();
                     err.span_suggestion_verbose(
                         self.prev_token.span.until(self.token.span),
diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs
index fc907760531..6601011665b 100644
--- a/compiler/rustc_parse/src/parser/stmt.rs
+++ b/compiler/rustc_parse/src/parser/stmt.rs
@@ -40,8 +40,8 @@ impl<'a> Parser<'a> {
         }))
     }
 
-    /// If `force_collect` is [`ForceCollect::Yes`], forces collection of tokens regardless of whether
-    /// or not we have attributes
+    /// If `force_collect` is [`ForceCollect::Yes`], forces collection of tokens regardless of
+    /// whether or not we have attributes.
     // Public for `cfg_eval` macro expansion.
     pub fn parse_stmt_without_recovery(
         &mut self,
@@ -51,18 +51,12 @@ impl<'a> Parser<'a> {
         let attrs = self.parse_outer_attributes()?;
         let lo = self.token.span;
 
-        // Don't use `maybe_whole` so that we have precise control
-        // over when we bump the parser
-        if let token::Interpolated(nt) = &self.token.kind
-            && let token::NtStmt(stmt) = &nt.0
-        {
-            let mut stmt = stmt.clone();
-            self.bump();
+        maybe_whole!(self, NtStmt, |stmt| {
             stmt.visit_attrs(|stmt_attrs| {
                 attrs.prepend_to_nt_inner(stmt_attrs);
             });
-            return Ok(Some(stmt.into_inner()));
-        }
+            Some(stmt.into_inner())
+        });
 
         if self.token.is_keyword(kw::Mut) && self.is_keyword_ahead(1, &[kw::Let]) {
             self.bump();
@@ -539,7 +533,7 @@ impl<'a> Parser<'a> {
         blk_mode: BlockCheckMode,
         can_be_struct_literal: bool,
     ) -> PResult<'a, (AttrVec, P<Block>)> {
-        maybe_whole!(self, NtBlock, |x| (AttrVec::new(), x));
+        maybe_whole!(self, NtBlock, |block| (AttrVec::new(), block));
 
         let maybe_ident = self.prev_token.clone();
         self.maybe_recover_unexpected_block_label();
@@ -643,7 +637,7 @@ impl<'a> Parser<'a> {
         recover: AttemptLocalParseRecovery,
     ) -> PResult<'a, Option<Stmt>> {
         // Skip looking for a trailing semicolon when we have an interpolated statement.
-        maybe_whole!(self, NtStmt, |x| Some(x.into_inner()));
+        maybe_whole!(self, NtStmt, |stmt| Some(stmt.into_inner()));
 
         let Some(mut stmt) = self.parse_stmt_without_recovery(true, ForceCollect::No)? else {
             return Ok(None);
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
index 2385c18c089..1cea32cb90f 100644
--- a/compiler/rustc_parse/src/parser/ty.rs
+++ b/compiler/rustc_parse/src/parser/ty.rs
@@ -250,7 +250,7 @@ impl<'a> Parser<'a> {
     ) -> PResult<'a, P<Ty>> {
         let allow_qpath_recovery = recover_qpath == RecoverQPath::Yes;
         maybe_recover_from_interpolated_ty_qpath!(self, allow_qpath_recovery);
-        maybe_whole!(self, NtTy, |x| x);
+        maybe_whole!(self, NtTy, |ty| ty);
 
         let lo = self.token.span;
         let mut impl_dyn_multi = false;