Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

13 files changed, 173 insertions, 122 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 4d80f904a..9317579f7 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -33,7 +33,6 @@ use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_span::source_map::{respan, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
-use std::convert::TryFrom;
 use std::fmt;
 use std::mem;
 use thin_vec::{thin_vec, ThinVec};
@@ -573,7 +572,7 @@ impl Pat {
             PatKind::MacCall(mac) => TyKind::MacCall(mac.clone()),
             // `&mut? P` can be reinterpreted as `&mut? T` where `T` is `P` reparsed as a type.
             PatKind::Ref(pat, mutbl) => {
-                pat.to_ty().map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?
+                pat.to_ty().map(|ty| TyKind::Ref(None, MutTy { ty, mutbl: *mutbl }))?
             }
             // A slice/array pattern `[P]` can be reparsed as `[T]`, an unsized array,
             // when `P` can be reparsed as a type `T`.
@@ -1194,7 +1193,7 @@ impl Expr {
             ExprKind::Paren(expr) => expr.to_ty().map(TyKind::Paren)?,
 
             ExprKind::AddrOf(BorrowKind::Ref, mutbl, expr) => {
-                expr.to_ty().map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?
+                expr.to_ty().map(|ty| TyKind::Ref(None, MutTy { ty, mutbl: *mutbl }))?
             }
 
             ExprKind::Repeat(expr, expr_len) => {
@@ -1308,6 +1307,7 @@ impl Expr {
 pub struct Closure {
     pub binder: ClosureBinder,
     pub capture_clause: CaptureBy,
+    pub constness: Const,
     pub asyncness: Async,
     pub movability: Movability,
     pub fn_decl: P<FnDecl>,
@@ -1735,8 +1735,10 @@ pub enum StrStyle {
 /// A literal in a meta item.
 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
 pub struct MetaItemLit {
-    /// The original literal token as written in source code.
-    pub token_lit: token::Lit,
+    /// The original literal as written in the source code.
+    pub symbol: Symbol,
+    /// The original suffix as written in the source code.
+    pub suffix: Option<Symbol>,
     /// The "semantic" representation of the literal lowered from the original tokens.
     /// Strings are unescaped, hexadecimal forms are eliminated, etc.
     pub kind: LitKind,
@@ -1746,13 +1748,14 @@ pub struct MetaItemLit {
 /// Similar to `MetaItemLit`, but restricted to string literals.
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub struct StrLit {
-    /// The original literal token as written in source code.
-    pub style: StrStyle,
+    /// The original literal as written in source code.
     pub symbol: Symbol,
+    /// The original suffix as written in source code.
     pub suffix: Option<Symbol>,
-    pub span: Span,
-    /// The unescaped "semantic" representation of the literal lowered from the original token.
+    /// The semantic (unescaped) representation of the literal.
     pub symbol_unescaped: Symbol,
+    pub style: StrStyle,
+    pub span: Span,
 }
 
 impl StrLit {
@@ -1798,8 +1801,9 @@ pub enum LitKind {
     /// A string literal (`"foo"`). The symbol is unescaped, and so may differ
     /// from the original token's symbol.
     Str(Symbol, StrStyle),
-    /// A byte string (`b"foo"`).
-    ByteStr(Lrc<[u8]>),
+    /// A byte string (`b"foo"`). Not stored as a symbol because it might be
+    /// non-utf8, and symbols only allow utf8 strings.
+    ByteStr(Lrc<[u8]>, StrStyle),
     /// A byte char (`b'f'`).
     Byte(u8),
     /// A character literal (`'a'`).
@@ -1824,7 +1828,7 @@ impl LitKind {
 
     /// Returns `true` if this literal is byte literal string.
     pub fn is_bytestr(&self) -> bool {
-        matches!(self, LitKind::ByteStr(_))
+        matches!(self, LitKind::ByteStr(..))
     }
 
     /// Returns `true` if this is a numeric literal.
@@ -2028,7 +2032,8 @@ impl Clone for Ty {
 impl Ty {
     pub fn peel_refs(&self) -> &Self {
         let mut final_ty = self;
-        while let TyKind::Rptr(_, MutTy { ty, .. }) = &final_ty.kind {
+        while let TyKind::Ref(_, MutTy { ty, .. }) | TyKind::Ptr(MutTy { ty, .. }) = &final_ty.kind
+        {
             final_ty = ty;
         }
         final_ty
@@ -2055,7 +2060,7 @@ pub enum TyKind {
     /// A raw pointer (`*const T` or `*mut T`).
     Ptr(MutTy),
     /// A reference (`&'a T` or `&'a mut T`).
-    Rptr(Option<Lifetime>, MutTy),
+    Ref(Option<Lifetime>, MutTy),
     /// A bare function (e.g., `fn(usize) -> bool`).
     BareFn(P<BareFnTy>),
     /// The never type (`!`).
@@ -2167,10 +2172,10 @@ impl fmt::Display for InlineAsmTemplatePiece {
                 Ok(())
             }
             Self::Placeholder { operand_idx, modifier: Some(modifier), .. } => {
-                write!(f, "{{{}:{}}}", operand_idx, modifier)
+                write!(f, "{{{operand_idx}:{modifier}}}")
             }
             Self::Placeholder { operand_idx, modifier: None, .. } => {
-                write!(f, "{{{}}}", operand_idx)
+                write!(f, "{{{operand_idx}}}")
             }
         }
     }
@@ -2182,7 +2187,7 @@ impl InlineAsmTemplatePiece {
         use fmt::Write;
         let mut out = String::new();
         for p in s.iter() {
-            let _ = write!(out, "{}", p);
+            let _ = write!(out, "{p}");
         }
         out
     }
@@ -2283,7 +2288,7 @@ impl Param {
             if ident.name == kw::SelfLower {
                 return match self.ty.kind {
                     TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
-                    TyKind::Rptr(lt, MutTy { ref ty, mutbl }) if ty.kind.is_implicit_self() => {
+                    TyKind::Ref(lt, MutTy { ref ty, mutbl }) if ty.kind.is_implicit_self() => {
                         Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
                     }
                     _ => Some(respan(
@@ -2316,7 +2321,7 @@ impl Param {
                 Mutability::Not,
                 P(Ty {
                     id: DUMMY_NODE_ID,
-                    kind: TyKind::Rptr(lt, MutTy { ty: infer_ty, mutbl }),
+                    kind: TyKind::Ref(lt, MutTy { ty: infer_ty, mutbl }),
                     span,
                     tokens: None,
                 }),
@@ -2463,7 +2468,7 @@ pub enum ModKind {
     Unloaded,
 }
 
-#[derive(Copy, Clone, Encodable, Decodable, Debug)]
+#[derive(Copy, Clone, Encodable, Decodable, Debug, Default)]
 pub struct ModSpans {
     /// `inner_span` covers the body of the module; for a file module, its the whole file.
     /// For an inline module, its the span inside the `{ ... }`, not including the curly braces.
@@ -2471,12 +2476,6 @@ pub struct ModSpans {
     pub inject_use_span: Span,
 }
 
-impl Default for ModSpans {
-    fn default() -> ModSpans {
-        ModSpans { inner_span: Default::default(), inject_use_span: Default::default() }
-    }
-}
-
 /// Foreign module declaration.
 ///
 /// E.g., `extern { .. }` or `extern "C" { .. }`.
@@ -2557,10 +2556,9 @@ pub enum AttrStyle {
 }
 
 rustc_index::newtype_index! {
-    pub struct AttrId {
-        ENCODABLE = custom
-        DEBUG_FORMAT = "AttrId({})"
-    }
+    #[custom_encodable]
+    #[debug_format = "AttrId({})]"]
+    pub struct AttrId {}
 }
 
 impl<S: Encoder> Encodable<S> for AttrId {
@@ -2747,8 +2745,19 @@ impl Item {
 /// `extern` qualifier on a function item or function type.
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub enum Extern {
+    /// No explicit extern keyword was used
+    ///
+    /// E.g. `fn foo() {}`
     None,
+    /// An explicit extern keyword was used, but with implicit ABI
+    ///
+    /// E.g. `extern fn foo() {}`
+    ///
+    /// This is just `extern "C"` (see `rustc_target::spec::abi::Abi::FALLBACK`)
     Implicit(Span),
+    /// An explicit extern keyword was used with an explicit ABI
+    ///
+    /// E.g. `extern "C" fn foo() {}`
     Explicit(StrLit, Span),
 }
 
@@ -2767,9 +2776,13 @@ impl Extern {
 /// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub struct FnHeader {
+    /// The `unsafe` keyword, if any
     pub unsafety: Unsafe,
+    /// The `async` keyword, if any
     pub asyncness: Async,
+    /// The `const` keyword, if any
     pub constness: Const,
+    /// The `extern` keyword and corresponding ABI string, if any
     pub ext: Extern,
 }
 
@@ -3101,7 +3114,7 @@ mod size_asserts {
     static_assert_size!(ItemKind, 112);
     static_assert_size!(LitKind, 24);
     static_assert_size!(Local, 72);
-    static_assert_size!(MetaItemLit, 48);
+    static_assert_size!(MetaItemLit, 40);
     static_assert_size!(Param, 40);
     static_assert_size!(Pat, 88);
     static_assert_size!(Path, 24);
diff --git a/compiler/rustc_ast/src/ast_traits.rs b/compiler/rustc_ast/src/ast_traits.rs
index 1b31be07f..4dc9c30a2 100644
--- a/compiler/rustc_ast/src/ast_traits.rs
+++ b/compiler/rustc_ast/src/ast_traits.rs
@@ -214,7 +214,7 @@ impl HasTokens for Attribute {
         match &self.kind {
             AttrKind::Normal(normal) => normal.tokens.as_ref(),
             kind @ AttrKind::DocComment(..) => {
-                panic!("Called tokens on doc comment attr {:?}", kind)
+                panic!("Called tokens on doc comment attr {kind:?}")
             }
         }
     }
@@ -222,7 +222,7 @@ impl HasTokens for Attribute {
         Some(match &mut self.kind {
             AttrKind::Normal(normal) => &mut normal.tokens,
             kind @ AttrKind::DocComment(..) => {
-                panic!("Called tokens_mut on doc comment attr {:?}", kind)
+                panic!("Called tokens_mut on doc comment attr {kind:?}")
             }
         })
     }
diff --git a/compiler/rustc_ast/src/attr/mod.rs b/compiler/rustc_ast/src/attr/mod.rs
index 057cc26b5..c6b6207b3 100644
--- a/compiler/rustc_ast/src/attr/mod.rs
+++ b/compiler/rustc_ast/src/attr/mod.rs
@@ -1,15 +1,15 @@
 //! Functions dealing with attributes and meta items.
 
-use crate::ast;
 use crate::ast::{AttrArgs, AttrArgsEq, AttrId, AttrItem, AttrKind, AttrStyle, AttrVec, Attribute};
 use crate::ast::{DelimArgs, Expr, ExprKind, LitKind, MetaItemLit};
 use crate::ast::{MacDelimiter, MetaItem, MetaItemKind, NestedMetaItem, NormalAttr};
-use crate::ast::{Path, PathSegment, StrStyle, DUMMY_NODE_ID};
+use crate::ast::{Path, PathSegment, DUMMY_NODE_ID};
 use crate::ptr::P;
 use crate::token::{self, CommentKind, Delimiter, Token};
 use crate::tokenstream::{DelimSpan, Spacing, TokenTree};
 use crate::tokenstream::{LazyAttrTokenStream, TokenStream};
 use crate::util::comments;
+use crate::util::literal::escape_string_symbol;
 use rustc_data_structures::sync::WorkerLocal;
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -310,7 +310,7 @@ impl Attribute {
             AttrKind::Normal(normal) => normal
                 .tokens
                 .as_ref()
-                .unwrap_or_else(|| panic!("attribute is missing tokens: {:?}", self))
+                .unwrap_or_else(|| panic!("attribute is missing tokens: {self:?}"))
                 .to_attr_token_stream()
                 .to_tokenstream(),
             &AttrKind::DocComment(comment_kind, data) => TokenStream::new(vec![TokenTree::Token(
@@ -321,18 +321,6 @@ impl Attribute {
     }
 }
 
-/* Constructors */
-
-pub fn mk_name_value_item_str(ident: Ident, str: Symbol, str_span: Span) -> MetaItem {
-    mk_name_value_item(ident, LitKind::Str(str, ast::StrStyle::Cooked), str_span)
-}
-
-pub fn mk_name_value_item(ident: Ident, kind: LitKind, lit_span: Span) -> MetaItem {
-    let lit = MetaItemLit { token_lit: kind.to_token_lit(), kind, span: lit_span };
-    let span = ident.span.to(lit_span);
-    MetaItem { path: Path::from_ident(ident), kind: MetaItemKind::NameValue(lit), span }
-}
-
 pub struct AttrIdGenerator(WorkerLocal<Cell<u32>>);
 
 #[cfg(debug_assertions)]
@@ -408,7 +396,7 @@ pub fn mk_attr_name_value_str(
     val: Symbol,
     span: Span,
 ) -> Attribute {
-    let lit = LitKind::Str(val, StrStyle::Cooked).to_token_lit();
+    let lit = token::Lit::new(token::Str, escape_string_symbol(val), None);
     let expr = P(Expr {
         id: DUMMY_NODE_ID,
         kind: ExprKind::Lit(lit),
diff --git a/compiler/rustc_ast/src/expand/allocator.rs b/compiler/rustc_ast/src/expand/allocator.rs
index 1976e4ad3..359394963 100644
--- a/compiler/rustc_ast/src/expand/allocator.rs
+++ b/compiler/rustc_ast/src/expand/allocator.rs
@@ -9,8 +9,8 @@ pub enum AllocatorKind {
 impl AllocatorKind {
     pub fn fn_name(&self, base: Symbol) -> String {
         match *self {
-            AllocatorKind::Global => format!("__rg_{}", base),
-            AllocatorKind::Default => format!("__rdl_{}", base),
+            AllocatorKind::Global => format!("__rg_{base}"),
+            AllocatorKind::Default => format!("__rdl_{base}"),
         }
     }
 }
diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index a45ee6067..77f342d1e 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -459,7 +459,7 @@ pub fn noop_visit_ty<T: MutVisitor>(ty: &mut P<Ty>, vis: &mut T) {
         TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err | TyKind::Never | TyKind::CVarArgs => {}
         TyKind::Slice(ty) => vis.visit_ty(ty),
         TyKind::Ptr(mt) => vis.visit_mt(mt),
-        TyKind::Rptr(lt, mt) => {
+        TyKind::Ref(lt, mt) => {
             visit_opt(lt, |lt| noop_visit_lifetime(lt, vis));
             vis.visit_mt(mt);
         }
@@ -1362,6 +1362,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
         ExprKind::Closure(box Closure {
             binder,
             capture_clause: _,
+            constness,
             asyncness,
             movability: _,
             fn_decl,
@@ -1370,6 +1371,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
             fn_arg_span: _,
         }) => {
             vis.visit_closure_binder(binder);
+            visit_constness(constness, vis);
             vis.visit_asyncness(asyncness);
             vis.visit_fn_decl(fn_decl);
             vis.visit_expr(body);
diff --git a/compiler/rustc_ast/src/node_id.rs b/compiler/rustc_ast/src/node_id.rs
index 7b5acc3f4..daa82996b 100644
--- a/compiler/rustc_ast/src/node_id.rs
+++ b/compiler/rustc_ast/src/node_id.rs
@@ -8,9 +8,8 @@ rustc_index::newtype_index! {
     /// This is later turned into [`DefId`] and `HirId` for the HIR.
     ///
     /// [`DefId`]: rustc_span::def_id::DefId
-    pub struct NodeId {
-        DEBUG_FORMAT = "NodeId({})"
-    }
+    #[debug_format = "NodeId({})"]
+    pub struct NodeId {}
 }
 
 rustc_data_structures::define_id_collections!(NodeMap, NodeSet, NodeMapEntry, NodeId);
diff --git a/compiler/rustc_ast/src/ptr.rs b/compiler/rustc_ast/src/ptr.rs
index 30481eddf..4b2850336 100644
--- a/compiler/rustc_ast/src/ptr.rs
+++ b/compiler/rustc_ast/src/ptr.rs
@@ -22,7 +22,6 @@
 //!   Moreover, a switch to, e.g., `P<'a, T>` would be easy and mostly automated.
 
 use std::fmt::{self, Debug, Display};
-use std::iter::FromIterator;
 use std::ops::{Deref, DerefMut};
 use std::{slice, vec};
 
diff --git a/compiler/rustc_ast/src/token.rs b/compiler/rustc_ast/src/token.rs
index c0cc4e79a..f947ae4d0 100644
--- a/compiler/rustc_ast/src/token.rs
+++ b/compiler/rustc_ast/src/token.rs
@@ -114,7 +114,7 @@ impl Lit {
                 if let NtExpr(expr) | NtLiteral(expr) = &**nt
                 && let ast::ExprKind::Lit(token_lit) = expr.kind =>
             {
-                Some(token_lit.clone())
+                Some(token_lit)
             }
             _ => None,
         }
@@ -125,27 +125,27 @@ impl fmt::Display for Lit {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let Lit { kind, symbol, suffix } = *self;
         match kind {
-            Byte => write!(f, "b'{}'", symbol)?,
-            Char => write!(f, "'{}'", symbol)?,
-            Str => write!(f, "\"{}\"", symbol)?,
+            Byte => write!(f, "b'{symbol}'")?,
+            Char => write!(f, "'{symbol}'")?,
+            Str => write!(f, "\"{symbol}\"")?,
             StrRaw(n) => write!(
                 f,
                 "r{delim}\"{string}\"{delim}",
                 delim = "#".repeat(n as usize),
                 string = symbol
             )?,
-            ByteStr => write!(f, "b\"{}\"", symbol)?,
+            ByteStr => write!(f, "b\"{symbol}\"")?,
             ByteStrRaw(n) => write!(
                 f,
                 "br{delim}\"{string}\"{delim}",
                 delim = "#".repeat(n as usize),
                 string = symbol
             )?,
-            Integer | Float | Bool | Err => write!(f, "{}", symbol)?,
+            Integer | Float | Bool | Err => write!(f, "{symbol}")?,
         }
 
         if let Some(suffix) = suffix {
-            write!(f, "{}", suffix)?;
+            write!(f, "{suffix}")?;
         }
 
         Ok(())
@@ -379,6 +379,10 @@ impl Token {
         }
     }
 
+    pub fn is_range_separator(&self) -> bool {
+        [DotDot, DotDotDot, DotDotEq].contains(&self.kind)
+    }
+
     pub fn is_op(&self) -> bool {
         match self.kind {
             Eq | Lt | Le | EqEq | Ne | Ge | Gt | AndAnd | OrOr | Not | Tilde | BinOp(_)
@@ -752,7 +756,7 @@ impl Token {
                 _ => return None,
             },
             SingleQuote => match joint.kind {
-                Ident(name, false) => Lifetime(Symbol::intern(&format!("'{}", name))),
+                Ident(name, false) => Lifetime(Symbol::intern(&format!("'{name}"))),
                 _ => return None,
             },
 
diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs
index 482c30295..fabd43a16 100644
--- a/compiler/rustc_ast/src/tokenstream.rs
+++ b/compiler/rustc_ast/src/tokenstream.rs
@@ -258,8 +258,7 @@ impl AttrTokenStream {
 
                         assert!(
                             found,
-                            "Failed to find trailing delimited group in: {:?}",
-                            target_tokens
+                            "Failed to find trailing delimited group in: {target_tokens:?}"
                         );
                     }
                     let mut flat: SmallVec<[_; 1]> = SmallVec::new();
@@ -362,7 +361,7 @@ impl TokenStream {
     }
 }
 
-impl iter::FromIterator<TokenTree> for TokenStream {
+impl FromIterator<TokenTree> for TokenStream {
     fn from_iter<I: IntoIterator<Item = TokenTree>>(iter: I) -> Self {
         TokenStream::new(iter.into_iter().collect::<Vec<TokenTree>>())
     }
diff --git a/compiler/rustc_ast/src/util/comments.rs b/compiler/rustc_ast/src/util/comments.rs
index 35454c3a6..275ed02c2 100644
--- a/compiler/rustc_ast/src/util/comments.rs
+++ b/compiler/rustc_ast/src/util/comments.rs
@@ -51,7 +51,7 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
         if i != 0 || j != lines.len() { Some((i, j)) } else { None }
     }
 
-    fn get_horizontal_trim<'a>(lines: &'a [&str], kind: CommentKind) -> Option<String> {
+    fn get_horizontal_trim(lines: &[&str], kind: CommentKind) -> Option<String> {
         let mut i = usize::MAX;
         let mut first = true;
 
diff --git a/compiler/rustc_ast/src/util/literal.rs b/compiler/rustc_ast/src/util/literal.rs
index f6f186b51..74b842ac9 100644
--- a/compiler/rustc_ast/src/util/literal.rs
+++ b/compiler/rustc_ast/src/util/literal.rs
@@ -1,11 +1,31 @@
 //! Code related to parsing literals.
 
-use crate::ast::{self, LitKind, MetaItemLit};
+use crate::ast::{self, LitKind, MetaItemLit, StrStyle};
 use crate::token::{self, Token};
 use rustc_lexer::unescape::{byte_from_char, unescape_byte, unescape_char, unescape_literal, Mode};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
-use std::ascii;
+use std::{ascii, fmt, str};
+
+// Escapes a string, represented as a symbol. Reuses the original symbol,
+// avoiding interning, if no changes are required.
+pub fn escape_string_symbol(symbol: Symbol) -> Symbol {
+    let s = symbol.as_str();
+    let escaped = s.escape_default().to_string();
+    if s == escaped { symbol } else { Symbol::intern(&escaped) }
+}
+
+// Escapes a char.
+pub fn escape_char_symbol(ch: char) -> Symbol {
+    let s: String = ch.escape_default().map(Into::<char>::into).collect();
+    Symbol::intern(&s)
+}
+
+// Escapes a byte string.
+pub fn escape_byte_str_symbol(bytes: &[u8]) -> Symbol {
+    let s = bytes.escape_ascii().to_string();
+    Symbol::intern(&s)
+}
 
 #[derive(Debug)]
 pub enum LitError {
@@ -14,7 +34,7 @@ pub enum LitError {
     InvalidIntSuffix,
     InvalidFloatSuffix,
     NonDecimalFloat(u32),
-    IntTooLarge,
+    IntTooLarge(u32),
 }
 
 impl LitKind {
@@ -115,9 +135,9 @@ impl LitKind {
                     }
                 });
                 error?;
-                LitKind::ByteStr(buf.into())
+                LitKind::ByteStr(buf.into(), StrStyle::Cooked)
             }
-            token::ByteStrRaw(_) => {
+            token::ByteStrRaw(n) => {
                 let s = symbol.as_str();
                 let bytes = if s.contains('\r') {
                     let mut buf = Vec::with_capacity(s.len());
@@ -136,69 +156,95 @@ impl LitKind {
                     symbol.to_string().into_bytes()
                 };
 
-                LitKind::ByteStr(bytes.into())
+                LitKind::ByteStr(bytes.into(), StrStyle::Raw(n))
             }
             token::Err => LitKind::Err,
         })
     }
+}
 
-    /// Attempts to recover a token from semantic literal.
-    /// This function is used when the original token doesn't exist (e.g. the literal is created
-    /// by an AST-based macro) or unavailable (e.g. from HIR pretty-printing).
-    pub fn to_token_lit(&self) -> token::Lit {
-        let (kind, symbol, suffix) = match *self {
-            LitKind::Str(symbol, ast::StrStyle::Cooked) => {
-                // Don't re-intern unless the escaped string is different.
-                let s = symbol.as_str();
-                let escaped = s.escape_default().to_string();
-                let symbol = if s == escaped { symbol } else { Symbol::intern(&escaped) };
-                (token::Str, symbol, None)
-            }
-            LitKind::Str(symbol, ast::StrStyle::Raw(n)) => (token::StrRaw(n), symbol, None),
-            LitKind::ByteStr(ref bytes) => {
-                let string = bytes.escape_ascii().to_string();
-                (token::ByteStr, Symbol::intern(&string), None)
+impl fmt::Display for LitKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            LitKind::Byte(b) => {
+                let b: String = ascii::escape_default(b).map(Into::<char>::into).collect();
+                write!(f, "b'{b}'")?;
             }
-            LitKind::Byte(byte) => {
-                let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
-                (token::Byte, Symbol::intern(&string), None)
+            LitKind::Char(ch) => write!(f, "'{}'", escape_char_symbol(ch))?,
+            LitKind::Str(sym, StrStyle::Cooked) => write!(f, "\"{}\"", escape_string_symbol(sym))?,
+            LitKind::Str(sym, StrStyle::Raw(n)) => write!(
+                f,
+                "r{delim}\"{string}\"{delim}",
+                delim = "#".repeat(n as usize),
+                string = sym
+            )?,
+            LitKind::ByteStr(ref bytes, StrStyle::Cooked) => {
+                write!(f, "b\"{}\"", escape_byte_str_symbol(bytes))?
             }
-            LitKind::Char(ch) => {
-                let string: String = ch.escape_default().map(Into::<char>::into).collect();
-                (token::Char, Symbol::intern(&string), None)
+            LitKind::ByteStr(ref bytes, StrStyle::Raw(n)) => {
+                // Unwrap because raw byte string literals can only contain ASCII.
+                let symbol = str::from_utf8(bytes).unwrap();
+                write!(
+                    f,
+                    "br{delim}\"{string}\"{delim}",
+                    delim = "#".repeat(n as usize),
+                    string = symbol
+                )?;
             }
             LitKind::Int(n, ty) => {
-                let suffix = match ty {
-                    ast::LitIntType::Unsigned(ty) => Some(ty.name()),
-                    ast::LitIntType::Signed(ty) => Some(ty.name()),
-                    ast::LitIntType::Unsuffixed => None,
-                };
-                (token::Integer, sym::integer(n), suffix)
+                write!(f, "{n}")?;
+                match ty {
+                    ast::LitIntType::Unsigned(ty) => write!(f, "{}", ty.name())?,
+                    ast::LitIntType::Signed(ty) => write!(f, "{}", ty.name())?,
+                    ast::LitIntType::Unsuffixed => {}
+                }
             }
             LitKind::Float(symbol, ty) => {
-                let suffix = match ty {
-                    ast::LitFloatType::Suffixed(ty) => Some(ty.name()),
-                    ast::LitFloatType::Unsuffixed => None,
-                };
-                (token::Float, symbol, suffix)
+                write!(f, "{symbol}")?;
+                match ty {
+                    ast::LitFloatType::Suffixed(ty) => write!(f, "{}", ty.name())?,
+                    ast::LitFloatType::Unsuffixed => {}
+                }
             }
-            LitKind::Bool(value) => {
-                let symbol = if value { kw::True } else { kw::False };
-                (token::Bool, symbol, None)
+            LitKind::Bool(b) => write!(f, "{}", if b { "true" } else { "false" })?,
+            LitKind::Err => {
+                // This only shows up in places like `-Zunpretty=hir` output, so we
+                // don't bother to produce something useful.
+                write!(f, "<bad-literal>")?;
             }
-            // This only shows up in places like `-Zunpretty=hir` output, so we
-            // don't bother to produce something useful.
-            LitKind::Err => (token::Err, Symbol::intern("<bad-literal>"), None),
-        };
+        }
 
-        token::Lit::new(kind, symbol, suffix)
+        Ok(())
     }
 }
 
 impl MetaItemLit {
-    /// Converts token literal into a meta item literal.
+    /// Converts a token literal into a meta item literal.
     pub fn from_token_lit(token_lit: token::Lit, span: Span) -> Result<MetaItemLit, LitError> {
-        Ok(MetaItemLit { token_lit, kind: LitKind::from_token_lit(token_lit)?, span })
+        Ok(MetaItemLit {
+            symbol: token_lit.symbol,
+            suffix: token_lit.suffix,
+            kind: LitKind::from_token_lit(token_lit)?,
+            span,
+        })
+    }
+
+    /// Cheaply converts a meta item literal into a token literal.
+    pub fn as_token_lit(&self) -> token::Lit {
+        let kind = match self.kind {
+            LitKind::Bool(_) => token::Bool,
+            LitKind::Str(_, ast::StrStyle::Cooked) => token::Str,
+            LitKind::Str(_, ast::StrStyle::Raw(n)) => token::StrRaw(n),
+            LitKind::ByteStr(_, ast::StrStyle::Cooked) => token::ByteStr,
+            LitKind::ByteStr(_, ast::StrStyle::Raw(n)) => token::ByteStrRaw(n),
+            LitKind::Byte(_) => token::Byte,
+            LitKind::Char(_) => token::Char,
+            LitKind::Int(..) => token::Integer,
+            LitKind::Float(..) => token::Float,
+            LitKind::Err => token::Err,
+        };
+
+        token::Lit::new(kind, self.symbol, self.suffix)
     }
 
     /// Converts an arbitrary token into meta item literal.
@@ -287,6 +333,6 @@ fn integer_lit(symbol: Symbol, suffix: Option<Symbol>) -> Result<LitKind, LitErr
         // but these kinds of errors are already reported by the lexer.
         let from_lexer =
             base < 10 && s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
-        if from_lexer { LitError::LexerError } else { LitError::IntTooLarge }
+        if from_lexer { LitError::LexerError } else { LitError::IntTooLarge(base) }
     })
 }
diff --git a/compiler/rustc_ast/src/util/parser.rs b/compiler/rustc_ast/src/util/parser.rs
index 819f1884a..4f7099c7b 100644
--- a/compiler/rustc_ast/src/util/parser.rs
+++ b/compiler/rustc_ast/src/util/parser.rs
@@ -304,7 +304,7 @@ impl ExprPrecedence {
             | ExprPrecedence::Yeet => PREC_JUMP,
 
             // `Range` claims to have higher precedence than `Assign`, but `x .. x = x` fails to
-            // parse, instead of parsing as `(x .. x) = x`.  Giving `Range` a lower precedence
+            // parse, instead of parsing as `(x .. x) = x`. Giving `Range` a lower precedence
             // ensures that `pprust` will add parentheses in the right places to get the desired
             // parse.
             ExprPrecedence::Range => PREC_RANGE,
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index 991eb489f..e8823eff8 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -92,7 +92,7 @@ impl<'a> FnKind<'a> {
 #[derive(Copy, Clone, Debug)]
 pub enum LifetimeCtxt {
     /// Appears in a reference type.
-    Rptr,
+    Ref,
     /// Appears as a bound on a type or another lifetime.
     Bound,
     /// Appears as a generic argument.
@@ -396,8 +396,8 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
     match &typ.kind {
         TyKind::Slice(ty) | TyKind::Paren(ty) => visitor.visit_ty(ty),
         TyKind::Ptr(mutable_type) => visitor.visit_ty(&mutable_type.ty),
-        TyKind::Rptr(opt_lifetime, mutable_type) => {
-            walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Rptr);
+        TyKind::Ref(opt_lifetime, mutable_type) => {
+            walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Ref);
             visitor.visit_ty(&mutable_type.ty)
         }
         TyKind::Tup(tuple_element_types) => {
@@ -836,6 +836,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             binder,
             capture_clause: _,
             asyncness: _,
+            constness: _,
             movability: _,
             fn_decl,
             body,