From b93a2dd0efeb00238543fd199ebdb8bb0f96bad7 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Sat, 26 Oct 2024 18:51:15 +0300
Subject: [PATCH] expand: Stop using artificial `ast::Item` for macros loaded
 from metadata

---
 compiler/rustc_expand/src/mbe/macro_rules.rs  | 98 ++++++++-----------
 compiler/rustc_metadata/src/creader.rs        |  4 +-
 .../src/rmeta/decoder/cstore_impl.rs          | 28 ++----
 .../rustc_resolve/src/build_reduced_graph.rs  |  4 +-
 compiler/rustc_resolve/src/def_collector.rs   |  6 +-
 compiler/rustc_resolve/src/macros.rs          | 40 +++++---
 src/librustdoc/clean/inline.rs                | 26 ++---
 src/librustdoc/html/format.rs                 |  8 +-
 8 files changed, 94 insertions(+), 120 deletions(-)

diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index f40f99b6ea12..fcc90c3ce0dd 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -3,12 +3,11 @@ use std::collections::hash_map::Entry;
 use std::{mem, slice};
 
 use ast::token::IdentIsRaw;
-use rustc_ast as ast;
 use rustc_ast::token::NtPatKind::*;
 use rustc_ast::token::TokenKind::*;
 use rustc_ast::token::{self, Delimiter, NonterminalKind, Token, TokenKind};
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
-use rustc_ast::{DUMMY_NODE_ID, NodeId};
+use rustc_ast::{self as ast, DUMMY_NODE_ID, NodeId};
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, TransparencyError};
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
@@ -370,34 +369,32 @@ pub(super) fn try_match_macro<'matcher, T: Tracker<'matcher>>(
 pub fn compile_declarative_macro(
     sess: &Session,
     features: &Features,
-    def: &ast::Item,
+    macro_def: &ast::MacroDef,
+    ident: Ident,
+    attrs: &[ast::Attribute],
+    span: Span,
+    node_id: NodeId,
     edition: Edition,
 ) -> (SyntaxExtension, Vec<(usize, Span)>) {
-    debug!("compile_declarative_macro: {:?}", def);
     let mk_syn_ext = |expander| {
         SyntaxExtension::new(
             sess,
             features,
             SyntaxExtensionKind::LegacyBang(expander),
-            def.span,
+            span,
             Vec::new(),
             edition,
-            def.ident.name,
-            &def.attrs,
-            def.id != DUMMY_NODE_ID,
+            ident.name,
+            attrs,
+            node_id != DUMMY_NODE_ID,
         )
     };
     let dummy_syn_ext = |guar| (mk_syn_ext(Box::new(DummyExpander(guar))), Vec::new());
 
     let dcx = sess.dcx();
-    let lhs_nm = Ident::new(sym::lhs, def.span);
-    let rhs_nm = Ident::new(sym::rhs, def.span);
+    let lhs_nm = Ident::new(sym::lhs, span);
+    let rhs_nm = Ident::new(sym::rhs, span);
     let tt_spec = Some(NonterminalKind::TT);
-
-    let macro_def = match &def.kind {
-        ast::ItemKind::MacroDef(def) => def,
-        _ => unreachable!(),
-    };
     let macro_rules = macro_def.macro_rules;
 
     // Parse the macro_rules! invocation
@@ -410,25 +407,22 @@ pub fn compile_declarative_macro(
     let argument_gram = vec![
         mbe::TokenTree::Sequence(DelimSpan::dummy(), mbe::SequenceRepetition {
             tts: vec![
-                mbe::TokenTree::MetaVarDecl(def.span, lhs_nm, tt_spec),
-                mbe::TokenTree::token(token::FatArrow, def.span),
-                mbe::TokenTree::MetaVarDecl(def.span, rhs_nm, tt_spec),
+                mbe::TokenTree::MetaVarDecl(span, lhs_nm, tt_spec),
+                mbe::TokenTree::token(token::FatArrow, span),
+                mbe::TokenTree::MetaVarDecl(span, rhs_nm, tt_spec),
             ],
-            separator: Some(Token::new(
-                if macro_rules { token::Semi } else { token::Comma },
-                def.span,
-            )),
-            kleene: mbe::KleeneToken::new(mbe::KleeneOp::OneOrMore, def.span),
+            separator: Some(Token::new(if macro_rules { token::Semi } else { token::Comma }, span)),
+            kleene: mbe::KleeneToken::new(mbe::KleeneOp::OneOrMore, span),
             num_captures: 2,
         }),
         // to phase into semicolon-termination instead of semicolon-separation
         mbe::TokenTree::Sequence(DelimSpan::dummy(), mbe::SequenceRepetition {
             tts: vec![mbe::TokenTree::token(
                 if macro_rules { token::Semi } else { token::Comma },
-                def.span,
+                span,
             )],
             separator: None,
-            kleene: mbe::KleeneToken::new(mbe::KleeneOp::ZeroOrMore, def.span),
+            kleene: mbe::KleeneToken::new(mbe::KleeneOp::ZeroOrMore, span),
             num_captures: 0,
         }),
     ];
@@ -460,7 +454,7 @@ pub fn compile_declarative_macro(
                 };
 
                 let s = parse_failure_msg(&token, track.get_expected_token());
-                let sp = token.span.substitute_dummy(def.span);
+                let sp = token.span.substitute_dummy(span);
                 let mut err = sess.dcx().struct_span_err(sp, s);
                 err.span_label(sp, msg);
                 annotate_doc_comment(&mut err, sess.source_map(), sp);
@@ -468,7 +462,7 @@ pub fn compile_declarative_macro(
                 return dummy_syn_ext(guar);
             }
             Error(sp, msg) => {
-                let guar = sess.dcx().span_err(sp.substitute_dummy(def.span), msg);
+                let guar = sess.dcx().span_err(sp.substitute_dummy(span), msg);
                 return dummy_syn_ext(guar);
             }
             ErrorReported(guar) => {
@@ -489,7 +483,7 @@ pub fn compile_declarative_macro(
                         &TokenStream::new(vec![tt.clone()]),
                         true,
                         sess,
-                        def.id,
+                        node_id,
                         features,
                         edition,
                     )
@@ -497,13 +491,13 @@ pub fn compile_declarative_macro(
                     .unwrap();
                     // We don't handle errors here, the driver will abort
                     // after parsing/expansion. We can report every error in every macro this way.
-                    check_emission(check_lhs_nt_follows(sess, def, &tt));
+                    check_emission(check_lhs_nt_follows(sess, node_id, &tt));
                     return tt;
                 }
-                sess.dcx().span_bug(def.span, "wrong-structured lhs")
+                sess.dcx().span_bug(span, "wrong-structured lhs")
             })
             .collect::<Vec<mbe::TokenTree>>(),
-        _ => sess.dcx().span_bug(def.span, "wrong-structured lhs"),
+        _ => sess.dcx().span_bug(span, "wrong-structured lhs"),
     };
 
     let rhses = match &argument_map[&MacroRulesNormalizedIdent::new(rhs_nm)] {
@@ -515,17 +509,17 @@ pub fn compile_declarative_macro(
                         &TokenStream::new(vec![tt.clone()]),
                         false,
                         sess,
-                        def.id,
+                        node_id,
                         features,
                         edition,
                     )
                     .pop()
                     .unwrap();
                 }
-                sess.dcx().span_bug(def.span, "wrong-structured rhs")
+                sess.dcx().span_bug(span, "wrong-structured rhs")
             })
             .collect::<Vec<mbe::TokenTree>>(),
-        _ => sess.dcx().span_bug(def.span, "wrong-structured rhs"),
+        _ => sess.dcx().span_bug(span, "wrong-structured rhs"),
     };
 
     for rhs in &rhses {
@@ -537,15 +531,9 @@ pub fn compile_declarative_macro(
         check_emission(check_lhs_no_empty_seq(sess, slice::from_ref(lhs)));
     }
 
-    check_emission(macro_check::check_meta_variables(
-        &sess.psess,
-        def.id,
-        def.span,
-        &lhses,
-        &rhses,
-    ));
+    check_emission(macro_check::check_meta_variables(&sess.psess, node_id, span, &lhses, &rhses));
 
-    let (transparency, transparency_error) = attr::find_transparency(&def.attrs, macro_rules);
+    let (transparency, transparency_error) = attr::find_transparency(attrs, macro_rules);
     match transparency_error {
         Some(TransparencyError::UnknownTransparency(value, span)) => {
             dcx.span_err(span, format!("unknown macro transparency: `{value}`"));
@@ -564,7 +552,7 @@ pub fn compile_declarative_macro(
 
     // Compute the spans of the macro rules for unused rule linting.
     // Also, we are only interested in non-foreign macros.
-    let rule_spans = if def.id != DUMMY_NODE_ID {
+    let rule_spans = if node_id != DUMMY_NODE_ID {
         lhses
             .iter()
             .zip(rhses.iter())
@@ -590,15 +578,15 @@ pub fn compile_declarative_macro(
                 mbe::TokenTree::Delimited(.., delimited) => {
                     mbe::macro_parser::compute_locs(&delimited.tts)
                 }
-                _ => sess.dcx().span_bug(def.span, "malformed macro lhs"),
+                _ => sess.dcx().span_bug(span, "malformed macro lhs"),
             }
         })
         .collect();
 
     let expander = Box::new(MacroRulesMacroExpander {
-        name: def.ident,
-        span: def.span,
-        node_id: def.id,
+        name: ident,
+        span,
+        node_id,
         transparency,
         lhses,
         rhses,
@@ -608,13 +596,13 @@ pub fn compile_declarative_macro(
 
 fn check_lhs_nt_follows(
     sess: &Session,
-    def: &ast::Item,
+    node_id: NodeId,
     lhs: &mbe::TokenTree,
 ) -> Result<(), ErrorGuaranteed> {
     // lhs is going to be like TokenTree::Delimited(...), where the
     // entire lhs is those tts. Or, it can be a "bare sequence", not wrapped in parens.
     if let mbe::TokenTree::Delimited(.., delimited) = lhs {
-        check_matcher(sess, def, &delimited.tts)
+        check_matcher(sess, node_id, &delimited.tts)
     } else {
         let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
         Err(sess.dcx().span_err(lhs.span(), msg))
@@ -686,12 +674,12 @@ fn check_rhs(sess: &Session, rhs: &mbe::TokenTree) -> Result<(), ErrorGuaranteed
 
 fn check_matcher(
     sess: &Session,
-    def: &ast::Item,
+    node_id: NodeId,
     matcher: &[mbe::TokenTree],
 ) -> Result<(), ErrorGuaranteed> {
     let first_sets = FirstSets::new(matcher);
     let empty_suffix = TokenSet::empty();
-    check_matcher_core(sess, def, &first_sets, matcher, &empty_suffix)?;
+    check_matcher_core(sess, node_id, &first_sets, matcher, &empty_suffix)?;
     Ok(())
 }
 
@@ -1028,7 +1016,7 @@ impl<'tt> TokenSet<'tt> {
 // see `FirstSets::new`.
 fn check_matcher_core<'tt>(
     sess: &Session,
-    def: &ast::Item,
+    node_id: NodeId,
     first_sets: &FirstSets<'tt>,
     matcher: &'tt [mbe::TokenTree],
     follow: &TokenSet<'tt>,
@@ -1082,7 +1070,7 @@ fn check_matcher_core<'tt>(
                     token::CloseDelim(d.delim),
                     span.close,
                 ));
-                check_matcher_core(sess, def, first_sets, &d.tts, &my_suffix)?;
+                check_matcher_core(sess, node_id, first_sets, &d.tts, &my_suffix)?;
                 // don't track non NT tokens
                 last.replace_with_irrelevant();
 
@@ -1114,7 +1102,7 @@ fn check_matcher_core<'tt>(
                 // At this point, `suffix_first` is built, and
                 // `my_suffix` is some TokenSet that we can use
                 // for checking the interior of `seq_rep`.
-                let next = check_matcher_core(sess, def, first_sets, &seq_rep.tts, my_suffix)?;
+                let next = check_matcher_core(sess, node_id, first_sets, &seq_rep.tts, my_suffix)?;
                 if next.maybe_empty {
                     last.add_all(&next);
                 } else {
@@ -1144,7 +1132,7 @@ fn check_matcher_core<'tt>(
                     // macro. (See #86567.)
                     // Macros defined in the current crate have a real node id,
                     // whereas macros from an external crate have a dummy id.
-                    if def.id != DUMMY_NODE_ID
+                    if node_id != DUMMY_NODE_ID
                         && matches!(kind, NonterminalKind::Pat(PatParam { inferred: true }))
                         && matches!(
                             next_token,
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 8adec7554a83..16623915c401 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -28,7 +28,7 @@ use rustc_session::lint::{self, BuiltinLintDiag};
 use rustc_session::output::validate_crate_name;
 use rustc_session::search_paths::PathKind;
 use rustc_span::edition::Edition;
-use rustc_span::symbol::{Symbol, sym};
+use rustc_span::symbol::{Ident, Symbol, sym};
 use rustc_span::{DUMMY_SP, Span};
 use rustc_target::spec::{PanicStrategy, Target, TargetTriple};
 use tracing::{debug, info, trace};
@@ -97,7 +97,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
 }
 
 pub enum LoadedMacro {
-    MacroDef(ast::Item, Edition),
+    MacroDef { def: MacroDef, ident: Ident, attrs: AttrVec, span: Span, edition: Edition },
     ProcMacro(SyntaxExtension),
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 71c7231a7882..926eb4f6210b 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -1,7 +1,6 @@
 use std::any::Any;
 use std::mem;
 
-use rustc_ast as ast;
 use rustc_attr::Deprecation;
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{CtorKind, DefKind, Res};
@@ -592,27 +591,16 @@ impl CStore {
 
         let data = self.get_crate_data(id.krate);
         if data.root.is_proc_macro_crate() {
-            return LoadedMacro::ProcMacro(data.load_proc_macro(id.index, tcx));
-        }
-
-        let span = data.get_span(id.index, sess);
-
-        LoadedMacro::MacroDef(
-            ast::Item {
+            LoadedMacro::ProcMacro(data.load_proc_macro(id.index, tcx))
+        } else {
+            LoadedMacro::MacroDef {
+                def: data.get_macro(id.index, sess),
                 ident: data.item_ident(id.index, sess),
-                id: ast::DUMMY_NODE_ID,
-                span,
                 attrs: data.get_item_attrs(id.index, sess).collect(),
-                kind: ast::ItemKind::MacroDef(data.get_macro(id.index, sess)),
-                vis: ast::Visibility {
-                    span: span.shrink_to_lo(),
-                    kind: ast::VisibilityKind::Inherited,
-                    tokens: None,
-                },
-                tokens: None,
-            },
-            data.root.edition,
-        )
+                span: data.get_span(id.index, sess),
+                edition: data.root.edition,
+            }
+        }
     }
 
     pub fn def_span_untracked(&self, def_id: DefId, sess: &Session) -> Span {
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 031ffaed808b..bdf940a04b56 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -177,7 +177,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
         let loaded_macro = self.cstore().load_macro_untracked(def_id, self.tcx);
         let macro_data = match loaded_macro {
-            LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
+            LoadedMacro::MacroDef { def, ident, attrs, span, edition } => {
+                self.compile_macro(&def, ident, &attrs, span, ast::DUMMY_NODE_ID, edition)
+            }
             LoadedMacro::ProcMacro(ext) => MacroData::new(Lrc::new(ext)),
         };
 
diff --git a/compiler/rustc_resolve/src/def_collector.rs b/compiler/rustc_resolve/src/def_collector.rs
index 0047f2c4b51e..a825458dc894 100644
--- a/compiler/rustc_resolve/src/def_collector.rs
+++ b/compiler/rustc_resolve/src/def_collector.rs
@@ -199,8 +199,10 @@ impl<'a, 'ra, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'ra, 'tcx> {
             },
             ItemKind::Const(..) => DefKind::Const,
             ItemKind::Fn(..) | ItemKind::Delegation(..) => DefKind::Fn,
-            ItemKind::MacroDef(..) => {
-                let macro_data = self.resolver.compile_macro(i, self.resolver.tcx.sess.edition());
+            ItemKind::MacroDef(def) => {
+                let edition = self.resolver.tcx.sess.edition();
+                let macro_data =
+                    self.resolver.compile_macro(def, i.ident, &i.attrs, i.span, i.id, edition);
                 let macro_kind = macro_data.ext.macro_kind();
                 opt_macro_data = Some(macro_data);
                 DefKind::Macro(macro_kind)
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index a9ebffea8a10..1dc27776cb0f 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -1122,9 +1122,25 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     /// Compile the macro into a `SyntaxExtension` and its rule spans.
     ///
     /// Possibly replace its expander to a pre-defined one for built-in macros.
-    pub(crate) fn compile_macro(&mut self, item: &ast::Item, edition: Edition) -> MacroData {
-        let (mut ext, mut rule_spans) =
-            compile_declarative_macro(self.tcx.sess, self.tcx.features(), item, edition);
+    pub(crate) fn compile_macro(
+        &mut self,
+        macro_def: &ast::MacroDef,
+        ident: Ident,
+        attrs: &[ast::Attribute],
+        span: Span,
+        node_id: NodeId,
+        edition: Edition,
+    ) -> MacroData {
+        let (mut ext, mut rule_spans) = compile_declarative_macro(
+            self.tcx.sess,
+            self.tcx.features(),
+            macro_def,
+            ident,
+            attrs,
+            span,
+            node_id,
+            edition,
+        );
 
         if let Some(builtin_name) = ext.builtin_name {
             // The macro was marked with `#[rustc_builtin_macro]`.
@@ -1132,28 +1148,22 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 // The macro is a built-in, replace its expander function
                 // while still taking everything else from the source code.
                 // If we already loaded this builtin macro, give a better error message than 'no such builtin macro'.
-                match mem::replace(builtin_macro, BuiltinMacroState::AlreadySeen(item.span)) {
+                match mem::replace(builtin_macro, BuiltinMacroState::AlreadySeen(span)) {
                     BuiltinMacroState::NotYetSeen(builtin_ext) => {
                         ext.kind = builtin_ext;
                         rule_spans = Vec::new();
                     }
-                    BuiltinMacroState::AlreadySeen(span) => {
-                        self.dcx().emit_err(errors::AttemptToDefineBuiltinMacroTwice {
-                            span: item.span,
-                            note_span: span,
-                        });
+                    BuiltinMacroState::AlreadySeen(note_span) => {
+                        self.dcx()
+                            .emit_err(errors::AttemptToDefineBuiltinMacroTwice { span, note_span });
                     }
                 }
             } else {
-                self.dcx().emit_err(errors::CannotFindBuiltinMacroWithName {
-                    span: item.span,
-                    ident: item.ident,
-                });
+                self.dcx().emit_err(errors::CannotFindBuiltinMacroWithName { span, ident });
             }
         }
 
-        let ItemKind::MacroDef(def) = &item.kind else { unreachable!() };
-        MacroData { ext: Lrc::new(ext), rule_spans, macro_rules: def.macro_rules }
+        MacroData { ext: Lrc::new(ext), rule_spans, macro_rules: macro_def.macro_rules }
     }
 
     fn path_accessible(
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index e7f921eef7fc..97529e420e3b 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -248,9 +248,7 @@ pub(crate) fn record_extern_fqn(cx: &mut DocContext<'_>, did: DefId, kind: ItemT
         // Check to see if it is a macro 2.0 or built-in macro
         if matches!(
             CStore::from_tcx(cx.tcx).load_macro_untracked(did, cx.tcx),
-            LoadedMacro::MacroDef(def, _)
-                if matches!(&def.kind, ast::ItemKind::MacroDef(ast_def)
-                    if !ast_def.macro_rules)
+            LoadedMacro::MacroDef { def, .. } if !def.macro_rules
         ) {
             once(crate_name).chain(relative).collect()
         } else {
@@ -747,24 +745,12 @@ fn build_macro(
     is_doc_hidden: bool,
 ) -> clean::ItemKind {
     match CStore::from_tcx(cx.tcx).load_macro_untracked(def_id, cx.tcx) {
-        LoadedMacro::MacroDef(item_def, _) => match macro_kind {
+        LoadedMacro::MacroDef { def, .. } => match macro_kind {
             MacroKind::Bang => {
-                if let ast::ItemKind::MacroDef(ref def) = item_def.kind {
-                    let vis =
-                        cx.tcx.visibility(import_def_id.map(|d| d.to_def_id()).unwrap_or(def_id));
-                    clean::MacroItem(clean::Macro {
-                        source: utils::display_macro_source(
-                            cx,
-                            name,
-                            def,
-                            def_id,
-                            vis,
-                            is_doc_hidden,
-                        ),
-                    })
-                } else {
-                    unreachable!()
-                }
+                let vis = cx.tcx.visibility(import_def_id.map(|d| d.to_def_id()).unwrap_or(def_id));
+                clean::MacroItem(clean::Macro {
+                    source: utils::display_macro_source(cx, name, &def, def_id, vis, is_doc_hidden),
+                })
             }
             MacroKind::Derive | MacroKind::Attr => {
                 clean::ProcMacroItem(clean::ProcMacro { kind: macro_kind, helpers: Vec::new() })
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index ea2f930ab837..8e8e5c6ade8c 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -16,6 +16,7 @@ use itertools::Itertools;
 use rustc_attr::{ConstStability, StabilityLevel, StableSince};
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxHashSet;
+use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_metadata::creader::{CStore, LoadedMacro};
@@ -25,7 +26,6 @@ use rustc_span::symbol::kw;
 use rustc_span::{Symbol, sym};
 use rustc_target::spec::abi::Abi;
 use tracing::{debug, trace};
-use {rustc_ast as ast, rustc_hir as hir};
 
 use super::url_parts_builder::{UrlPartsBuilder, estimate_item_path_byte_length};
 use crate::clean::types::ExternalLocation;
@@ -554,10 +554,8 @@ fn generate_macro_def_id_path(
     // Check to see if it is a macro 2.0 or built-in macro.
     // More information in <https://rust-lang.github.io/rfcs/1584-macros.html>.
     let is_macro_2 = match cstore.load_macro_untracked(def_id, tcx) {
-        LoadedMacro::MacroDef(def, _) => {
-            // If `ast_def.macro_rules` is `true`, then it's not a macro 2.0.
-            matches!(&def.kind, ast::ItemKind::MacroDef(ast_def) if !ast_def.macro_rules)
-        }
+        // If `def.macro_rules` is `true`, then it's not a macro 2.0.
+        LoadedMacro::MacroDef { def, .. } => !def.macro_rules,
         _ => false,
     };