Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1

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

13 files changed, 230 insertions, 175 deletions

diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 6e093811f..e1da3ecde 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -6,7 +6,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Nonterminal};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{AssocCtxt, Visitor};
-use rustc_ast::{self as ast, Attribute, HasAttrs, Item, NodeId, PatKind};
+use rustc_ast::{self as ast, AttrVec, Attribute, HasAttrs, Item, NodeId, PatKind};
 use rustc_attr::{self as attr, Deprecation, Stability};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_data_structures::sync::{self, Lrc};
@@ -71,7 +71,7 @@ impl Annotatable {
         }
     }
 
-    pub fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    pub fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         match self {
             Annotatable::Item(item) => item.visit_attrs(f),
             Annotatable::TraitItem(trait_item) => trait_item.visit_attrs(f),
@@ -693,10 +693,6 @@ pub struct SyntaxExtension {
     pub span: Span,
     /// List of unstable features that are treated as stable inside this macro.
     pub allow_internal_unstable: Option<Lrc<[Symbol]>>,
-    /// Suppresses the `unsafe_code` lint for code produced by this macro.
-    pub allow_internal_unsafe: bool,
-    /// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) for this macro.
-    pub local_inner_macros: bool,
     /// The macro's stability info.
     pub stability: Option<Stability>,
     /// The macro's deprecation info.
@@ -708,6 +704,13 @@ pub struct SyntaxExtension {
     /// Built-in macros have a couple of special properties like availability
     /// in `#[no_implicit_prelude]` modules, so we have to keep this flag.
     pub builtin_name: Option<Symbol>,
+    /// Suppresses the `unsafe_code` lint for code produced by this macro.
+    pub allow_internal_unsafe: bool,
+    /// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) for this macro.
+    pub local_inner_macros: bool,
+    /// Should debuginfo for the macro be collapsed to the outermost expansion site (in other
+    /// words, was the macro definition annotated with `#[collapse_debuginfo]`)?
+    pub collapse_debuginfo: bool,
 }
 
 impl SyntaxExtension {
@@ -729,14 +732,15 @@ impl SyntaxExtension {
         SyntaxExtension {
             span: DUMMY_SP,
             allow_internal_unstable: None,
-            allow_internal_unsafe: false,
-            local_inner_macros: false,
             stability: None,
             deprecation: None,
             helper_attrs: Vec::new(),
             edition,
             builtin_name: None,
             kind,
+            allow_internal_unsafe: false,
+            local_inner_macros: false,
+            collapse_debuginfo: false,
         }
     }
 
@@ -754,12 +758,13 @@ impl SyntaxExtension {
         let allow_internal_unstable =
             attr::allow_internal_unstable(sess, &attrs).collect::<Vec<Symbol>>();
 
-        let mut local_inner_macros = false;
-        if let Some(macro_export) = sess.find_by_name(attrs, sym::macro_export) {
-            if let Some(l) = macro_export.meta_item_list() {
-                local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros);
-            }
-        }
+        let allow_internal_unsafe = sess.contains_name(attrs, sym::allow_internal_unsafe);
+        let local_inner_macros = sess
+            .find_by_name(attrs, sym::macro_export)
+            .and_then(|macro_export| macro_export.meta_item_list())
+            .map_or(false, |l| attr::list_contains_name(&l, sym::local_inner_macros));
+        let collapse_debuginfo = sess.contains_name(attrs, sym::collapse_debuginfo);
+        tracing::debug!(?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
 
         let (builtin_name, helper_attrs) = sess
             .find_by_name(attrs, sym::rustc_builtin_macro)
@@ -772,7 +777,7 @@ impl SyntaxExtension {
                 )
             })
             .unwrap_or_else(|| (None, helper_attrs));
-        let (stability, const_stability) = attr::find_stability(&sess, attrs, span);
+        let (stability, const_stability, body_stability) = attr::find_stability(&sess, attrs, span);
         if let Some((_, sp)) = const_stability {
             sess.parse_sess
                 .span_diagnostic
@@ -784,19 +789,31 @@ impl SyntaxExtension {
                 )
                 .emit();
         }
+        if let Some((_, sp)) = body_stability {
+            sess.parse_sess
+                .span_diagnostic
+                .struct_span_err(sp, "macros cannot have body stability attributes")
+                .span_label(sp, "invalid body stability attribute")
+                .span_label(
+                    sess.source_map().guess_head_span(span),
+                    "body stability attribute affects this macro",
+                )
+                .emit();
+        }
 
         SyntaxExtension {
             kind,
             span,
             allow_internal_unstable: (!allow_internal_unstable.is_empty())
                 .then(|| allow_internal_unstable.into()),
-            allow_internal_unsafe: sess.contains_name(attrs, sym::allow_internal_unsafe),
-            local_inner_macros,
             stability: stability.map(|(s, _)| s),
             deprecation: attr::find_deprecation(&sess, attrs).map(|(d, _)| d),
             helper_attrs,
             edition,
             builtin_name,
+            allow_internal_unsafe,
+            local_inner_macros,
+            collapse_debuginfo,
         }
     }
 
@@ -841,11 +858,12 @@ impl SyntaxExtension {
             call_site,
             self.span,
             self.allow_internal_unstable.clone(),
-            self.allow_internal_unsafe,
-            self.local_inner_macros,
             self.edition,
             macro_def_id,
             parent_module,
+            self.allow_internal_unsafe,
+            self.local_inner_macros,
+            self.collapse_debuginfo,
         )
     }
 }
@@ -1216,7 +1234,7 @@ pub fn expr_to_spanned_string<'a>(
                 );
                 Some((err, true))
             }
-            ast::LitKind::Err(_) => None,
+            ast::LitKind::Err => None,
             _ => Some((cx.struct_span_err(l.span, err_msg), false)),
         },
         ast::ExprKind::Err => None,
diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs
index fa3e2a4a5..50d2be3ce 100644
--- a/compiler/rustc_expand/src/build.rs
+++ b/compiler/rustc_expand/src/build.rs
@@ -3,6 +3,7 @@ use crate::base::ExtCtxt;
 use rustc_ast::attr;
 use rustc_ast::ptr::P;
 use rustc_ast::{self as ast, AttrVec, BlockCheckMode, Expr, LocalKind, PatKind, UnOp};
+use rustc_data_structures::sync::Lrc;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 
@@ -106,14 +107,13 @@ impl<'a> ExtCtxt<'a> {
         &self,
         span: Span,
         ident: Ident,
-        attrs: Vec<ast::Attribute>,
         bounds: ast::GenericBounds,
         default: Option<P<ast::Ty>>,
     ) -> ast::GenericParam {
         ast::GenericParam {
             ident: ident.with_span_pos(span),
             id: ast::DUMMY_NODE_ID,
-            attrs: attrs.into(),
+            attrs: AttrVec::new(),
             bounds,
             kind: ast::GenericParamKind::Type { default },
             is_placeholder: false,
@@ -178,8 +178,7 @@ impl<'a> ExtCtxt<'a> {
         ex: P<ast::Expr>,
     ) -> ast::Stmt {
         let pat = if mutbl {
-            let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Mut);
-            self.pat_ident_binding_mode(sp, ident, binding_mode)
+            self.pat_ident_binding_mode(sp, ident, ast::BindingAnnotation::MUT)
         } else {
             self.pat_ident(sp, ident)
         };
@@ -330,23 +329,38 @@ impl<'a> ExtCtxt<'a> {
         self.expr_struct(span, self.path_ident(span, id), fields)
     }
 
-    pub fn expr_lit(&self, span: Span, lit_kind: ast::LitKind) -> P<ast::Expr> {
+    fn expr_lit(&self, span: Span, lit_kind: ast::LitKind) -> P<ast::Expr> {
         let lit = ast::Lit::from_lit_kind(lit_kind, span);
         self.expr(span, ast::ExprKind::Lit(lit))
     }
+
     pub fn expr_usize(&self, span: Span, i: usize) -> P<ast::Expr> {
         self.expr_lit(
             span,
             ast::LitKind::Int(i as u128, ast::LitIntType::Unsigned(ast::UintTy::Usize)),
         )
     }
+
     pub fn expr_u32(&self, sp: Span, u: u32) -> P<ast::Expr> {
         self.expr_lit(sp, ast::LitKind::Int(u as u128, ast::LitIntType::Unsigned(ast::UintTy::U32)))
     }
+
     pub fn expr_bool(&self, sp: Span, value: bool) -> P<ast::Expr> {
         self.expr_lit(sp, ast::LitKind::Bool(value))
     }
 
+    pub fn expr_str(&self, sp: Span, s: Symbol) -> P<ast::Expr> {
+        self.expr_lit(sp, ast::LitKind::Str(s, ast::StrStyle::Cooked))
+    }
+
+    pub fn expr_char(&self, sp: Span, ch: char) -> P<ast::Expr> {
+        self.expr_lit(sp, ast::LitKind::Char(ch))
+    }
+
+    pub fn expr_byte_str(&self, sp: Span, bytes: Vec<u8>) -> P<ast::Expr> {
+        self.expr_lit(sp, ast::LitKind::ByteStr(Lrc::from(bytes)))
+    }
+
     /// `[expr1, expr2, ...]`
     pub fn expr_array(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
         self.expr(sp, ast::ExprKind::Array(exprs))
@@ -357,10 +371,6 @@ impl<'a> ExtCtxt<'a> {
         self.expr_addr_of(sp, self.expr_array(sp, exprs))
     }
 
-    pub fn expr_str(&self, sp: Span, s: Symbol) -> P<ast::Expr> {
-        self.expr_lit(sp, ast::LitKind::Str(s, ast::StrStyle::Cooked))
-    }
-
     pub fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr> {
         self.expr(sp, ast::ExprKind::Cast(expr, ty))
     }
@@ -434,17 +444,16 @@ impl<'a> ExtCtxt<'a> {
         self.pat(span, PatKind::Lit(expr))
     }
     pub fn pat_ident(&self, span: Span, ident: Ident) -> P<ast::Pat> {
-        let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Not);
-        self.pat_ident_binding_mode(span, ident, binding_mode)
+        self.pat_ident_binding_mode(span, ident, ast::BindingAnnotation::NONE)
     }
 
     pub fn pat_ident_binding_mode(
         &self,
         span: Span,
         ident: Ident,
-        bm: ast::BindingMode,
+        ann: ast::BindingAnnotation,
     ) -> P<ast::Pat> {
-        let pat = PatKind::Ident(bm, ident.with_span_pos(span), None);
+        let pat = PatKind::Ident(ann, ident.with_span_pos(span), None);
         self.pat(span, pat)
     }
     pub fn pat_path(&self, span: Span, path: ast::Path) -> P<ast::Pat> {
@@ -564,7 +573,7 @@ impl<'a> ExtCtxt<'a> {
         &self,
         span: Span,
         name: Ident,
-        attrs: Vec<ast::Attribute>,
+        attrs: ast::AttrVec,
         kind: ast::ItemKind,
     ) -> P<ast::Item> {
         // FIXME: Would be nice if our generated code didn't violate
@@ -592,7 +601,7 @@ impl<'a> ExtCtxt<'a> {
         mutbl: ast::Mutability,
         expr: P<ast::Expr>,
     ) -> P<ast::Item> {
-        self.item(span, name, Vec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
+        self.item(span, name, AttrVec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
     }
 
     pub fn item_const(
@@ -603,11 +612,11 @@ impl<'a> ExtCtxt<'a> {
         expr: P<ast::Expr>,
     ) -> P<ast::Item> {
         let def = ast::Defaultness::Final;
-        self.item(span, name, Vec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
+        self.item(span, name, AttrVec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
     }
 
     pub fn attribute(&self, mi: ast::MetaItem) -> ast::Attribute {
-        attr::mk_attr_outer(mi)
+        attr::mk_attr_outer(&self.sess.parse_sess.attr_id_generator, mi)
     }
 
     pub fn meta_word(&self, sp: Span, w: Symbol) -> ast::MetaItem {
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 3e1acf438..8d4e36407 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -2,9 +2,9 @@
 
 use rustc_ast::ptr::P;
 use rustc_ast::token::{Delimiter, Token, TokenKind};
-use rustc_ast::tokenstream::{AttrAnnotatedTokenStream, AttrAnnotatedTokenTree};
+use rustc_ast::tokenstream::{AttrTokenStream, AttrTokenTree};
 use rustc_ast::tokenstream::{DelimSpan, Spacing};
-use rustc_ast::tokenstream::{LazyTokenStream, TokenTree};
+use rustc_ast::tokenstream::{LazyAttrTokenStream, TokenTree};
 use rustc_ast::NodeId;
 use rustc_ast::{self as ast, AttrStyle, Attribute, HasAttrs, HasTokens, MetaItem};
 use rustc_attr as attr;
@@ -215,7 +215,7 @@ pub fn features(
     let features = match strip_unconfigured.configure_krate_attrs(krate.attrs) {
         None => {
             // The entire crate is unconfigured.
-            krate.attrs = Vec::new();
+            krate.attrs = ast::AttrVec::new();
             krate.items = Vec::new();
             Features::default()
         }
@@ -259,27 +259,27 @@ impl<'a> StripUnconfigured<'a> {
     fn try_configure_tokens<T: HasTokens>(&self, node: &mut T) {
         if self.config_tokens {
             if let Some(Some(tokens)) = node.tokens_mut() {
-                let attr_annotated_tokens = tokens.create_token_stream();
-                *tokens = LazyTokenStream::new(self.configure_tokens(&attr_annotated_tokens));
+                let attr_stream = tokens.to_attr_token_stream();
+                *tokens = LazyAttrTokenStream::new(self.configure_tokens(&attr_stream));
             }
         }
     }
 
-    fn configure_krate_attrs(&self, mut attrs: Vec<ast::Attribute>) -> Option<Vec<ast::Attribute>> {
+    fn configure_krate_attrs(&self, mut attrs: ast::AttrVec) -> Option<ast::AttrVec> {
         attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
         if self.in_cfg(&attrs) { Some(attrs) } else { None }
     }
 
-    /// Performs cfg-expansion on `stream`, producing a new `AttrAnnotatedTokenStream`.
+    /// Performs cfg-expansion on `stream`, producing a new `AttrTokenStream`.
     /// This is only used during the invocation of `derive` proc-macros,
     /// which require that we cfg-expand their entire input.
     /// Normal cfg-expansion operates on parsed AST nodes via the `configure` method
-    fn configure_tokens(&self, stream: &AttrAnnotatedTokenStream) -> AttrAnnotatedTokenStream {
-        fn can_skip(stream: &AttrAnnotatedTokenStream) -> bool {
-            stream.0.iter().all(|(tree, _spacing)| match tree {
-                AttrAnnotatedTokenTree::Attributes(_) => false,
-                AttrAnnotatedTokenTree::Token(_) => true,
-                AttrAnnotatedTokenTree::Delimited(_, _, inner) => can_skip(inner),
+    fn configure_tokens(&self, stream: &AttrTokenStream) -> AttrTokenStream {
+        fn can_skip(stream: &AttrTokenStream) -> bool {
+            stream.0.iter().all(|tree| match tree {
+                AttrTokenTree::Attributes(_) => false,
+                AttrTokenTree::Token(..) => true,
+                AttrTokenTree::Delimited(_, _, inner) => can_skip(inner),
             })
         }
 
@@ -290,38 +290,36 @@ impl<'a> StripUnconfigured<'a> {
         let trees: Vec<_> = stream
             .0
             .iter()
-            .flat_map(|(tree, spacing)| match tree.clone() {
-                AttrAnnotatedTokenTree::Attributes(mut data) => {
-                    let mut attrs: Vec<_> = std::mem::take(&mut data.attrs).into();
-                    attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
-                    data.attrs = attrs.into();
+            .flat_map(|tree| match tree.clone() {
+                AttrTokenTree::Attributes(mut data) => {
+                    data.attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
 
                     if self.in_cfg(&data.attrs) {
-                        data.tokens = LazyTokenStream::new(
-                            self.configure_tokens(&data.tokens.create_token_stream()),
+                        data.tokens = LazyAttrTokenStream::new(
+                            self.configure_tokens(&data.tokens.to_attr_token_stream()),
                         );
-                        Some((AttrAnnotatedTokenTree::Attributes(data), *spacing)).into_iter()
+                        Some(AttrTokenTree::Attributes(data)).into_iter()
                     } else {
                         None.into_iter()
                     }
                 }
-                AttrAnnotatedTokenTree::Delimited(sp, delim, mut inner) => {
+                AttrTokenTree::Delimited(sp, delim, mut inner) => {
                     inner = self.configure_tokens(&inner);
-                    Some((AttrAnnotatedTokenTree::Delimited(sp, delim, inner), *spacing))
+                    Some(AttrTokenTree::Delimited(sp, delim, inner))
                         .into_iter()
                 }
-                AttrAnnotatedTokenTree::Token(ref token) if let TokenKind::Interpolated(ref nt) = token.kind => {
+                AttrTokenTree::Token(ref token, _) if let TokenKind::Interpolated(ref nt) = token.kind => {
                     panic!(
                         "Nonterminal should have been flattened at {:?}: {:?}",
                         token.span, nt
                     );
                 }
-                AttrAnnotatedTokenTree::Token(token) => {
-                    Some((AttrAnnotatedTokenTree::Token(token), *spacing)).into_iter()
+                AttrTokenTree::Token(token, spacing) => {
+                    Some(AttrTokenTree::Token(token, spacing)).into_iter()
                 }
             })
             .collect();
-        AttrAnnotatedTokenStream::new(trees)
+        AttrTokenStream::new(trees)
     }
 
     /// Parse and expand all `cfg_attr` attributes into a list of attributes
@@ -390,7 +388,7 @@ impl<'a> StripUnconfigured<'a> {
         attr: &Attribute,
         (item, item_span): (ast::AttrItem, Span),
     ) -> Attribute {
-        let orig_tokens = attr.tokens().to_tokenstream();
+        let orig_tokens = attr.tokens();
 
         // We are taking an attribute of the form `#[cfg_attr(pred, attr)]`
         // and producing an attribute of the form `#[attr]`. We
@@ -406,27 +404,33 @@ impl<'a> StripUnconfigured<'a> {
         };
         let pound_span = pound_token.span;
 
-        let mut trees = vec![(AttrAnnotatedTokenTree::Token(pound_token), Spacing::Alone)];
+        let mut trees = vec![AttrTokenTree::Token(pound_token, Spacing::Alone)];
         if attr.style == AttrStyle::Inner {
             // For inner attributes, we do the same thing for the `!` in `#![some_attr]`
             let TokenTree::Token(bang_token @ Token { kind: TokenKind::Not, .. }, _) = orig_trees.next().unwrap() else {
                 panic!("Bad tokens for attribute {:?}", attr);
             };
-            trees.push((AttrAnnotatedTokenTree::Token(bang_token), Spacing::Alone));
+            trees.push(AttrTokenTree::Token(bang_token, Spacing::Alone));
         }
         // We don't really have a good span to use for the synthesized `[]`
         // in `#[attr]`, so just use the span of the `#` token.
-        let bracket_group = AttrAnnotatedTokenTree::Delimited(
+        let bracket_group = AttrTokenTree::Delimited(
             DelimSpan::from_single(pound_span),
             Delimiter::Bracket,
             item.tokens
                 .as_ref()
                 .unwrap_or_else(|| panic!("Missing tokens for {:?}", item))
-                .create_token_stream(),
+                .to_attr_token_stream(),
+        );
+        trees.push(bracket_group);
+        let tokens = Some(LazyAttrTokenStream::new(AttrTokenStream::new(trees)));
+        let attr = attr::mk_attr_from_item(
+            &self.sess.parse_sess.attr_id_generator,
+            item,
+            tokens,
+            attr.style,
+            item_span,
         );
-        trees.push((bracket_group, Spacing::Alone));
-        let tokens = Some(LazyTokenStream::new(AttrAnnotatedTokenStream::new(trees)));
-        let attr = attr::mk_attr_from_item(item, tokens, attr.style, item_span);
         if attr.has_name(sym::crate_type) {
             self.sess.parse_sess.buffer_lint(
                 rustc_lint_defs::builtin::DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
diff --git a/compiler/rustc_expand/src/errors.rs b/compiler/rustc_expand/src/errors.rs
new file mode 100644
index 000000000..0feae0deb
--- /dev/null
+++ b/compiler/rustc_expand/src/errors.rs
@@ -0,0 +1,48 @@
+use rustc_macros::SessionDiagnostic;
+use rustc_span::symbol::MacroRulesNormalizedIdent;
+use rustc_span::Span;
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::expr_repeat_no_syntax_vars)]
+pub(crate) struct NoSyntaxVarsExprRepeat {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::must_repeat_once)]
+pub(crate) struct MustRepeatOnce {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::count_repetition_misplaced)]
+pub(crate) struct CountRepetitionMisplaced {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::meta_var_expr_unrecognized_var)]
+pub(crate) struct MetaVarExprUnrecognizedVar {
+    #[primary_span]
+    pub span: Span,
+    pub key: MacroRulesNormalizedIdent,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::var_still_repeating)]
+pub(crate) struct VarStillRepeating {
+    #[primary_span]
+    pub span: Span,
+    pub ident: MacroRulesNormalizedIdent,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(expand::meta_var_dif_seq_matchers)]
+pub(crate) struct MetaVarsDifSeqMatchers {
+    #[primary_span]
+    pub span: Span,
+    pub msg: String,
+}
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index 93eeca5b2..c2add852a 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -11,7 +11,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{self, AssocCtxt, Visitor};
-use rustc_ast::{AssocItemKind, AstNodeWrapper, AttrStyle, ExprKind, ForeignItemKind};
+use rustc_ast::{AssocItemKind, AstNodeWrapper, AttrStyle, AttrVec, ExprKind, ForeignItemKind};
 use rustc_ast::{HasAttrs, HasNodeId};
 use rustc_ast::{Inline, ItemKind, MacArgs, MacStmtStyle, MetaItemKind, ModKind};
 use rustc_ast::{NestedMetaItem, NodeId, PatKind, StmtKind, TyKind};
@@ -306,7 +306,7 @@ pub struct Invocation {
 
 pub enum InvocationKind {
     Bang {
-        mac: ast::MacCall,
+        mac: P<ast::MacCall>,
         span: Span,
     },
     Attr {
@@ -1001,7 +1001,7 @@ enum AddSemicolon {
 /// of functionality used by `InvocationCollector`.
 trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
     type OutputTy = SmallVec<[Self; 1]>;
-    type AttrsTy: Deref<Target = [ast::Attribute]> = Vec<ast::Attribute>;
+    type AttrsTy: Deref<Target = [ast::Attribute]> = ast::AttrVec;
     const KIND: AstFragmentKind;
     fn to_annotatable(self) -> Annotatable;
     fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy;
@@ -1017,7 +1017,7 @@ trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
     fn is_mac_call(&self) -> bool {
         false
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         unreachable!()
     }
     fn pre_flat_map_node_collect_attr(_cfg: &StripUnconfigured<'_>, _attr: &ast::Attribute) {}
@@ -1046,7 +1046,7 @@ impl InvocationCollectorNode for P<ast::Item> {
     fn is_mac_call(&self) -> bool {
         matches!(self.kind, ItemKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
             ItemKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No),
@@ -1154,7 +1154,7 @@ impl InvocationCollectorNode for AstNodeWrapper<P<ast::AssocItem>, TraitItemTag>
     fn is_mac_call(&self) -> bool {
         matches!(self.wrapped.kind, AssocItemKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let item = self.wrapped.into_inner();
         match item.kind {
             AssocItemKind::MacCall(mac) => (mac, item.attrs, AddSemicolon::No),
@@ -1179,7 +1179,7 @@ impl InvocationCollectorNode for AstNodeWrapper<P<ast::AssocItem>, ImplItemTag>
     fn is_mac_call(&self) -> bool {
         matches!(self.wrapped.kind, AssocItemKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let item = self.wrapped.into_inner();
         match item.kind {
             AssocItemKind::MacCall(mac) => (mac, item.attrs, AddSemicolon::No),
@@ -1202,7 +1202,7 @@ impl InvocationCollectorNode for P<ast::ForeignItem> {
     fn is_mac_call(&self) -> bool {
         matches!(self.kind, ForeignItemKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
             ForeignItemKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No),
@@ -1323,7 +1323,7 @@ impl InvocationCollectorNode for ast::Stmt {
             StmtKind::Local(..) | StmtKind::Empty => false,
         }
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         // We pull macro invocations (both attributes and fn-like macro calls) out of their
         // `StmtKind`s and treat them as statement macro invocations, not as items or expressions.
         let (add_semicolon, mac, attrs) = match self.kind {
@@ -1333,7 +1333,7 @@ impl InvocationCollectorNode for ast::Stmt {
             }
             StmtKind::Item(item) => match item.into_inner() {
                 ast::Item { kind: ItemKind::MacCall(mac), attrs, .. } => {
-                    (mac.args.need_semicolon(), mac, attrs.into())
+                    (mac.args.need_semicolon(), mac, attrs)
                 }
                 _ => unreachable!(),
             },
@@ -1387,10 +1387,10 @@ impl InvocationCollectorNode for P<ast::Ty> {
     fn is_mac_call(&self) -> bool {
         matches!(self.kind, ast::TyKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
-            TyKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No),
+            TyKind::MacCall(mac) => (mac, AttrVec::new(), AddSemicolon::No),
             _ => unreachable!(),
         }
     }
@@ -1411,10 +1411,10 @@ impl InvocationCollectorNode for P<ast::Pat> {
     fn is_mac_call(&self) -> bool {
         matches!(self.kind, PatKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
-            PatKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No),
+            PatKind::MacCall(mac) => (mac, AttrVec::new(), AddSemicolon::No),
             _ => unreachable!(),
         }
     }
@@ -1439,7 +1439,7 @@ impl InvocationCollectorNode for P<ast::Expr> {
     fn is_mac_call(&self) -> bool {
         matches!(self.kind, ExprKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
             ExprKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No),
@@ -1466,7 +1466,7 @@ impl InvocationCollectorNode for AstNodeWrapper<P<ast::Expr>, OptExprTag> {
     fn is_mac_call(&self) -> bool {
         matches!(self.wrapped.kind, ast::ExprKind::MacCall(..))
     }
-    fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) {
+    fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.wrapped.into_inner();
         match node.kind {
             ExprKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No),
@@ -1512,7 +1512,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
         placeholder(fragment_kind, NodeId::placeholder_from_expn_id(expn_id), vis)
     }
 
-    fn collect_bang(&mut self, mac: ast::MacCall, kind: AstFragmentKind) -> AstFragment {
+    fn collect_bang(&mut self, mac: P<ast::MacCall>, kind: AstFragmentKind) -> AstFragment {
         // cache the macro call span so that it can be
         // easily adjusted for incremental compilation
         let span = mac.span();
@@ -1646,7 +1646,11 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     fn expand_cfg_attr(&self, node: &mut impl HasAttrs, attr: ast::Attribute, pos: usize) {
         node.visit_attrs(|attrs| {
-            attrs.splice(pos..pos, self.cfg().expand_cfg_attr(attr, false));
+            // Repeated `insert` calls is inefficient, but the number of
+            // insertions is almost always 0 or 1 in practice.
+            for cfg in self.cfg().expand_cfg_attr(attr, false).into_iter().rev() {
+                attrs.insert(pos, cfg)
+            }
         });
     }
 
diff --git a/compiler/rustc_expand/src/lib.rs b/compiler/rustc_expand/src/lib.rs
index 9d0232822..ffc9abe64 100644
--- a/compiler/rustc_expand/src/lib.rs
+++ b/compiler/rustc_expand/src/lib.rs
@@ -3,7 +3,7 @@
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
-#![feature(let_else)]
+#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(macro_metavar_expr)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_internals)]
@@ -15,6 +15,9 @@
 #[macro_use]
 extern crate rustc_macros;
 
+#[macro_use]
+extern crate tracing;
+
 extern crate proc_macro as pm;
 
 mod placeholders;
@@ -26,6 +29,7 @@ pub mod base;
 pub mod build;
 #[macro_use]
 pub mod config;
+pub mod errors;
 pub mod expand;
 pub mod module;
 pub mod proc_macro;
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs
index 4fa91dfea..c8bdc3931 100644
--- a/compiler/rustc_expand/src/mbe/macro_parser.rs
+++ b/compiler/rustc_expand/src/mbe/macro_parser.rs
@@ -430,7 +430,7 @@ impl TtParser {
                     }
                 }
                 MatcherLoc::Delimited => {
-                    // Entering the delimeter is trivial.
+                    // Entering the delimiter is trivial.
                     mp.idx += 1;
                     self.cur_mps.push(mp);
                 }
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index f7e1575af..7764ffd24 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -14,7 +14,7 @@ use rustc_ast::{NodeId, DUMMY_NODE_ID};
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, TransparencyError};
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
-use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
+use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder};
 use rustc_feature::Features;
 use rustc_lint_defs::builtin::{
     RUST_2021_INCOMPATIBLE_OR_PATTERNS, SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
@@ -32,7 +32,6 @@ use rustc_span::Span;
 use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 use std::{mem, slice};
-use tracing::debug;
 
 pub(crate) struct ParserAnyMacro<'a> {
     parser: Parser<'a>,
@@ -608,11 +607,7 @@ enum ExplainDocComment {
     },
 }
 
-fn annotate_doc_comment(
-    err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
-    sm: &SourceMap,
-    span: Span,
-) {
+fn annotate_doc_comment(err: &mut Diagnostic, sm: &SourceMap, span: Span) {
     if let Ok(src) = sm.span_to_snippet(span) {
         if src.starts_with("///") || src.starts_with("/**") {
             err.subdiagnostic(ExplainDocComment::Outer { span });
@@ -980,7 +975,7 @@ impl<'tt> TokenSet<'tt> {
         self.maybe_empty = false;
     }
 
-    // Adds `tok` to the set for `self`, marking sequence as non-empy.
+    // Adds `tok` to the set for `self`, marking sequence as non-empty.
     fn add_one(&mut self, tt: TtHandle<'tt>) {
         if !self.tokens.contains(&tt) {
             self.tokens.push(tt);
diff --git a/compiler/rustc_expand/src/mbe/metavar_expr.rs b/compiler/rustc_expand/src/mbe/metavar_expr.rs
index fc808401a..99fe47454 100644
--- a/compiler/rustc_expand/src/mbe/metavar_expr.rs
+++ b/compiler/rustc_expand/src/mbe/metavar_expr.rs
@@ -112,7 +112,7 @@ fn parse_depth<'sess>(
             "meta-variable expression depth must be a literal"
         ));
     };
-    if let Ok(lit_kind) = LitKind::from_lit_token(*lit)
+    if let Ok(lit_kind) = LitKind::from_token_lit(*lit)
         && let LitKind::Int(n_u128, LitIntType::Unsuffixed) = lit_kind
         && let Ok(n_usize) = usize::try_from(n_u128)
     {
diff --git a/compiler/rustc_expand/src/mbe/transcribe.rs b/compiler/rustc_expand/src/mbe/transcribe.rs
index e47ea83ac..bec6d1a2d 100644
--- a/compiler/rustc_expand/src/mbe/transcribe.rs
+++ b/compiler/rustc_expand/src/mbe/transcribe.rs
@@ -1,4 +1,8 @@
 use crate::base::ExtCtxt;
+use crate::errors::{
+    CountRepetitionMisplaced, MetaVarExprUnrecognizedVar, MetaVarsDifSeqMatchers, MustRepeatOnce,
+    NoSyntaxVarsExprRepeat, VarStillRepeating,
+};
 use crate::mbe::macro_parser::{MatchedNonterminal, MatchedSeq, MatchedTokenTree, NamedMatch};
 use crate::mbe::{self, MetaVarExpr};
 use rustc_ast::mut_visit::{self, MutVisitor};
@@ -165,11 +169,7 @@ pub(super) fn transcribe<'a>(
             seq @ mbe::TokenTree::Sequence(_, delimited) => {
                 match lockstep_iter_size(&seq, interp, &repeats) {
                     LockstepIterSize::Unconstrained => {
-                        return Err(cx.struct_span_err(
-                            seq.span(), /* blame macro writer */
-                            "attempted to repeat an expression containing no syntax variables \
-                             matched as repeating at this depth",
-                        ));
+                        return Err(cx.create_err(NoSyntaxVarsExprRepeat { span: seq.span() }));
                     }
 
                     LockstepIterSize::Contradiction(msg) => {
@@ -177,7 +177,7 @@ pub(super) fn transcribe<'a>(
                         // happens when two meta-variables are used in the same repetition in a
                         // sequence, but they come from different sequence matchers and repeat
                         // different amounts.
-                        return Err(cx.struct_span_err(seq.span(), &msg));
+                        return Err(cx.create_err(MetaVarsDifSeqMatchers { span: seq.span(), msg }));
                     }
 
                     LockstepIterSize::Constraint(len, _) => {
@@ -193,10 +193,7 @@ pub(super) fn transcribe<'a>(
                                 // FIXME: this really ought to be caught at macro definition
                                 // time... It happens when the Kleene operator in the matcher and
                                 // the body for the same meta-variable do not match.
-                                return Err(cx.struct_span_err(
-                                    sp.entire(),
-                                    "this must repeat at least once",
-                                ));
+                                return Err(cx.create_err(MustRepeatOnce { span: sp.entire() }));
                             }
                         } else {
                             // 0 is the initial counter (we have done 0 repetitions so far). `len`
@@ -239,10 +236,7 @@ pub(super) fn transcribe<'a>(
                         }
                         MatchedSeq(..) => {
                             // We were unable to descend far enough. This is an error.
-                            return Err(cx.struct_span_err(
-                                sp, /* blame the macro writer */
-                                &format!("variable '{}' is still repeating at this depth", ident),
-                            ));
+                            return Err(cx.create_err(VarStillRepeating { span: sp, ident }));
                         }
                     }
                 } else {
@@ -448,10 +442,7 @@ fn count_repetitions<'a>(
         match matched {
             MatchedTokenTree(_) | MatchedNonterminal(_) => {
                 if declared_lhs_depth == 0 {
-                    return Err(cx.struct_span_err(
-                        sp.entire(),
-                        "`count` can not be placed inside the inner-most repetition",
-                    ));
+                    return Err(cx.create_err(CountRepetitionMisplaced { span: sp.entire() }));
                 }
                 match depth_opt {
                     None => Ok(1),
@@ -499,12 +490,7 @@ where
 {
     let span = ident.span;
     let key = MacroRulesNormalizedIdent::new(ident);
-    interp.get(&key).ok_or_else(|| {
-        cx.struct_span_err(
-            span,
-            &format!("variable `{}` is not recognized in meta-variable expression", key),
-        )
-    })
+    interp.get(&key).ok_or_else(|| cx.create_err(MetaVarExprUnrecognizedVar { span, key }))
 }
 
 /// Used by meta-variable expressions when an user input is out of the actual declared bounds. For
diff --git a/compiler/rustc_expand/src/module.rs b/compiler/rustc_expand/src/module.rs
index 0315d1163..9002a24e4 100644
--- a/compiler/rustc_expand/src/module.rs
+++ b/compiler/rustc_expand/src/module.rs
@@ -1,6 +1,6 @@
 use crate::base::ModuleData;
 use rustc_ast::ptr::P;
-use rustc_ast::{token, Attribute, Inline, Item, ModSpans};
+use rustc_ast::{token, AttrVec, Attribute, Inline, Item, ModSpans};
 use rustc_errors::{struct_span_err, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_parse::new_parser_from_file;
 use rustc_parse::validate_attr;
@@ -48,7 +48,7 @@ pub(crate) fn parse_external_mod(
     span: Span, // The span to blame on errors.
     module: &ModuleData,
     mut dir_ownership: DirOwnership,
-    attrs: &mut Vec<Attribute>,
+    attrs: &mut AttrVec,
 ) -> ParsedExternalMod {
     // We bail on the first error, but that error does not cause a fatal error... (1)
     let result: Result<_, ModError<'_>> = try {
@@ -63,9 +63,9 @@ pub(crate) fn parse_external_mod(
 
         // Actually parse the external file as a module.
         let mut parser = new_parser_from_file(&sess.parse_sess, &mp.file_path, Some(span));
-        let (mut inner_attrs, items, inner_span) =
+        let (inner_attrs, items, inner_span) =
             parser.parse_mod(&token::Eof).map_err(|err| ModError::ParserError(err))?;
-        attrs.append(&mut inner_attrs);
+        attrs.extend(inner_attrs);
         (items, inner_span, mp.file_path)
     };
     // (1) ...instead, we return a dummy module.
diff --git a/compiler/rustc_expand/src/placeholders.rs b/compiler/rustc_expand/src/placeholders.rs
index 0d5d6ee07..3b0d5ddb9 100644
--- a/compiler/rustc_expand/src/placeholders.rs
+++ b/compiler/rustc_expand/src/placeholders.rs
@@ -15,16 +15,16 @@ pub fn placeholder(
     id: ast::NodeId,
     vis: Option<ast::Visibility>,
 ) -> AstFragment {
-    fn mac_placeholder() -> ast::MacCall {
-        ast::MacCall {
+    fn mac_placeholder() -> P<ast::MacCall> {
+        P(ast::MacCall {
             path: ast::Path { span: DUMMY_SP, segments: Vec::new(), tokens: None },
             args: P(ast::MacArgs::Empty),
             prior_type_ascription: None,
-        }
+        })
     }
 
     let ident = Ident::empty();
-    let attrs = Vec::new();
+    let attrs = ast::AttrVec::new();
     let vis = vis.unwrap_or(ast::Visibility {
         span: DUMMY_SP,
         kind: ast::VisibilityKind::Inherited,
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 7d9a4aed0..59a7b668a 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -6,7 +6,7 @@ use rustc_ast::tokenstream::{self, Spacing::*, TokenStream};
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
-use rustc_errors::{Diagnostic, MultiSpan, PResult};
+use rustc_errors::{MultiSpan, PResult};
 use rustc_parse::lexer::nfc_normalize;
 use rustc_parse::parse_stream_from_source_str;
 use rustc_session::parse::ParseSess;
@@ -15,7 +15,7 @@ use rustc_span::symbol::{self, sym, Symbol};
 use rustc_span::{BytePos, FileName, Pos, SourceFile, Span};
 
 use pm::bridge::{
-    server, DelimSpan, ExpnGlobals, Group, Ident, LitKind, Literal, Punct, TokenTree,
+    server, DelimSpan, Diagnostic, ExpnGlobals, Group, Ident, LitKind, Literal, Punct, TokenTree,
 };
 use pm::{Delimiter, Level, LineColumn};
 use std::ops::Bound;
@@ -368,8 +368,6 @@ impl server::Types for Rustc<'_, '_> {
     type FreeFunctions = FreeFunctions;
     type TokenStream = TokenStream;
     type SourceFile = Lrc<SourceFile>;
-    type MultiSpan = Vec<Span>;
-    type Diagnostic = Diagnostic;
     type Span = Span;
     type Symbol = Symbol;
 }
@@ -436,6 +434,21 @@ impl server::FreeFunctions for Rustc<'_, '_> {
             span: self.call_site,
         })
     }
+
+    fn emit_diagnostic(&mut self, diagnostic: Diagnostic<Self::Span>) {
+        let mut diag =
+            rustc_errors::Diagnostic::new(diagnostic.level.to_internal(), diagnostic.message);
+        diag.set_span(MultiSpan::from_spans(diagnostic.spans));
+        for child in diagnostic.children {
+            diag.sub(
+                child.level.to_internal(),
+                child.message,
+                MultiSpan::from_spans(child.spans),
+                None,
+            );
+        }
+        self.sess().span_diagnostic.emit_diagnostic(&mut diag);
+    }
 }
 
 impl server::TokenStream for Rustc<'_, '_> {
@@ -486,20 +499,26 @@ impl server::TokenStream for Rustc<'_, '_> {
         // We don't use `TokenStream::from_ast` as the tokenstream currently cannot
         // be recovered in the general case.
         match &expr.kind {
-            ast::ExprKind::Lit(l) if l.token.kind == token::Bool => Ok(
-                tokenstream::TokenStream::token_alone(token::Ident(l.token.symbol, false), l.span),
-            ),
+            ast::ExprKind::Lit(l) if l.token_lit.kind == token::Bool => {
+                Ok(tokenstream::TokenStream::token_alone(
+                    token::Ident(l.token_lit.symbol, false),
+                    l.span,
+                ))
+            }
             ast::ExprKind::Lit(l) => {
-                Ok(tokenstream::TokenStream::token_alone(token::Literal(l.token), l.span))
+                Ok(tokenstream::TokenStream::token_alone(token::Literal(l.token_lit), l.span))
             }
             ast::ExprKind::Unary(ast::UnOp::Neg, e) => match &e.kind {
-                ast::ExprKind::Lit(l) => match l.token {
+                ast::ExprKind::Lit(l) => match l.token_lit {
                     token::Lit { kind: token::Integer | token::Float, .. } => {
                         Ok(Self::TokenStream::from_iter([
                             // FIXME: The span of the `-` token is lost when
                             // parsing, so we cannot faithfully recover it here.
                             tokenstream::TokenTree::token_alone(token::BinOp(token::Minus), e.span),
-                            tokenstream::TokenTree::token_alone(token::Literal(l.token), l.span),
+                            tokenstream::TokenTree::token_alone(
+                                token::Literal(l.token_lit),
+                                l.span,
+                            ),
                         ]))
                     }
                     _ => Err(()),
@@ -577,38 +596,6 @@ impl server::SourceFile for Rustc<'_, '_> {
     }
 }
 
-impl server::MultiSpan for Rustc<'_, '_> {
-    fn new(&mut self) -> Self::MultiSpan {
-        vec![]
-    }
-
-    fn push(&mut self, spans: &mut Self::MultiSpan, span: Self::Span) {
-        spans.push(span)
-    }
-}
-
-impl server::Diagnostic for Rustc<'_, '_> {
-    fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic {
-        let mut diag = Diagnostic::new(level.to_internal(), msg);
-        diag.set_span(MultiSpan::from_spans(spans));
-        diag
-    }
-
-    fn sub(
-        &mut self,
-        diag: &mut Self::Diagnostic,
-        level: Level,
-        msg: &str,
-        spans: Self::MultiSpan,
-    ) {
-        diag.sub(level.to_internal(), msg, MultiSpan::from_spans(spans), None);
-    }
-
-    fn emit(&mut self, mut diag: Self::Diagnostic) {
-        self.sess().span_diagnostic.emit_diagnostic(&mut diag);
-    }
-}
-
 impl server::Span for Rustc<'_, '_> {
     fn debug(&mut self, span: Self::Span) -> String {
         if self.ecx.ecfg.span_debug {