rust-lang · ChayimFriedman2 · Aug 16, 2026 · Sep 7, 2026
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -72,6 +72,9 @@ jobs:
       - name: Install Rust Problem Matcher
         run: echo "::add-matcher::.github/rust.json"
 
+      - name: Check without building tests
+        run: cargo check --features in-rust-tree -p proc-macro-srv-cli
+
       - name: Test
         run: cargo test --features in-rust-tree -p proc-macro-srv -p proc-macro-srv-cli -p proc-macro-api -- --quiet
 

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/cfg/src/tests.rs b/crates/cfg/src/tests.rs
@@ -23,7 +23,7 @@ fn assert_parse_result(input: &str, expected: CfgExpr) {
         pred_ast.syntax(),
         DummyTestSpanMap,
         DUMMY,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
     );
     let cfg = CfgExpr::parse(&tt);
     assert_eq!(cfg, expected);
@@ -39,7 +39,7 @@ fn check_dnf(input: &str, expect: Expect) {
         pred_ast.syntax(),
         DummyTestSpanMap,
         DUMMY,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
     );
     let cfg = CfgExpr::parse(&tt);
     let actual = format!("#![cfg({})]", DnfExpr::new(&cfg));
@@ -57,7 +57,7 @@ fn check_why_inactive(input: &str, opts: &CfgOptions, expect: Expect) {
         pred_ast.syntax(),
         DummyTestSpanMap,
         DUMMY,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
     );
     let cfg = CfgExpr::parse(&tt);
     let dnf = DnfExpr::new(&cfg);
@@ -77,7 +77,7 @@ fn check_enable_hints(input: &str, opts: &CfgOptions, expected_hints: &[&str]) {
         pred_ast.syntax(),
         DummyTestSpanMap,
         DUMMY,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
     );
     let cfg = CfgExpr::parse(&tt);
     let dnf = DnfExpr::new(&cfg);

diff --git a/crates/hir-def/Cargo.toml b/crates/hir-def/Cargo.toml
@@ -56,3 +56,6 @@ in-rust-tree = ["hir-expand/in-rust-tree"]
 
 [lints]
 workspace = true
+
+[package.metadata.cargo-machete]
+ignored = ["ra-ap-rustc_parse_format"]
diff --git a/crates/hir-def/src/item_tree/attrs.rs b/crates/hir-def/src/item_tree/attrs.rs
@@ -21,7 +21,7 @@ use hir_expand::{
 use intern::{Interned, Symbol, sym};
 use syntax::{AstNode, ast};
 use syntax_bridge::DocCommentDesugarMode;
-use tt::token_to_literal;
+use tt::literal_from_str;
 
 use crate::item_tree::lower::Ctx;
 
@@ -64,11 +64,13 @@ impl AttrsOrCfg {
                 ast::Meta::KeyValueMeta(meta) => {
                     let span = span_map.span_for(path_range);
                     let input = meta.expr().and_then(|value| {
-                        if let ast::Expr::Literal(value) = value {
-                            Some(Box::new(AttrInput::Literal(token_to_literal(
+                        if let ast::Expr::Literal(value) = value
+                            && let Ok(lit) = literal_from_str(
                                 value.token().text(),
                                 span_map.span_for(value.syntax().text_range()),
-                            ))))
+                            )
+                        {
+                            Some(Box::new(AttrInput::Literal(lit)))
                         } else {
                             None
                         }
@@ -84,7 +86,8 @@ impl AttrsOrCfg {
                             .unwrap_or_else(|| meta.syntax().clone()),
                         span_map,
                         span,
-                        DocCommentDesugarMode::ProcMacro,
+                        // FIXME: This won't be correct once we support args for macro_rules attributes.
+                        DocCommentDesugarMode::Keep,
                     );
                     let input = Some(Box::new(AttrInput::TokenTree(tt)));
                     (span, input)

diff --git a/crates/hir-def/src/lib.rs b/crates/hir-def/src/lib.rs
@@ -9,11 +9,9 @@
 
 #![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
 
-#[cfg(feature = "in-rust-tree")]
-extern crate rustc_parse_format;
-
-#[cfg(not(feature = "in-rust-tree"))]
-extern crate ra_ap_rustc_parse_format as rustc_parse_format;
+stdx::rustc_crates! {
+    extern crate rustc_parse_format or ra_ap_rustc_parse_format;
+}
 
 pub extern crate ra_ap_rustc_abi as layout;
 pub extern crate ra_ap_rustc_abi as rustc_abi;

diff --git a/crates/hir-def/src/macro_expansion_tests/mbe/matching.rs b/crates/hir-def/src/macro_expansion_tests/mbe/matching.rs
@@ -257,3 +257,84 @@ macro_rules! m {
     "#]],
     );
 }
+
+#[test]
+fn doc_comment_is_ignored() {
+    check(
+        r#"
+macro_rules! m {
+    (
+        /// hello
+    ) => {};
+}
+
+m!();
+    "#,
+        expect![[r#"
+macro_rules! m {
+    (
+        /// hello
+    ) => {};
+}
+
+
+    "#]],
+    );
+    check(
+        r#"
+macro_rules! m {
+    () => {
+        macro_rules! m2 {
+            (/** hello */) => {}
+        }
+    };
+}
+
+m!();
+m2!();
+    "#,
+        expect![[r#"
+macro_rules! m {
+    () => {
+        macro_rules! m2 {
+            (/** hello */) => {}
+        }
+    };
+}
+
+macro_rules !m2 {
+    (/** hello */
+    ) = > {}
+}
+
+    "#]],
+    );
+    check(
+        r#"
+macro_rules! m {
+    ($($t:tt)*) => {
+        macro_rules! m2 {
+            ($($t)*) => {}
+        }
+    };
+}
+
+m!(/** hello */);
+m2!();
+    "#,
+        expect![[r#"
+macro_rules! m {
+    ($($t:tt)*) => {
+        macro_rules! m2 {
+            ($($t)*) => {}
+        }
+    };
+}
+
+macro_rules !m2 {
+    (#[doc = r" hello "]) = > {}
+}
+/* error: unexpected token in input */
+    "#]],
+    );
+}
diff --git a/crates/hir-def/src/macro_expansion_tests/mod.rs b/crates/hir-def/src/macro_expansion_tests/mod.rs
@@ -325,7 +325,7 @@ fn pretty_print_macro_expansion(
             (T!['{'], T!['}']) => "",
             (T![=], _) | (_, T![=]) => " ",
             (_, T!['{']) => " ",
-            (T![;] | T!['{'] | T!['}'], _) => "\n",
+            (T![;] | T!['{'] | T!['}'] | T![inner_doc_comment] | T![outer_doc_comment], _) => "\n",
             (_, T!['}']) => "\n",
             _ if (prev_kind.is_any_identifier()
                 || prev_kind == LIFETIME_IDENT

diff --git a/crates/hir-def/src/macro_expansion_tests/proc_macros.rs b/crates/hir-def/src/macro_expansion_tests/proc_macros.rs
@@ -50,7 +50,8 @@ mod foo {
 
 #[attr1]
 #[attr2] struct S;
-#[doc = " Foo"] mod foo {
+/// Foo
+mod foo {
     # ![foo]
     # ![doc = "123..."]
     # ![attr2]
@@ -293,8 +294,11 @@ struct S;
 #[doc = "doc attr"]
 struct S;
 
-#[doc = " doc string \\n with newline"]
-#[doc = "\n     MultiLines Doc\n     MultiLines Doc\n"]
+/// doc string \n with newline
+/**
+     MultiLines Doc
+     MultiLines Doc
+*/
 #[doc = "doc attr"] struct S;"##]],
     );
 }

diff --git a/crates/hir-expand/src/attrs.rs b/crates/hir-expand/src/attrs.rs
@@ -437,7 +437,7 @@ impl AttrId {
             tt.syntax(),
             SpanMap::RealSpanMap(&span_map),
             span_map.span_for_range(tt.syntax().text_range()),
-            DocCommentDesugarMode::ProcMacro,
+            DocCommentDesugarMode::Keep,
         );
         let Some((_, _, derive_tts)) =
             parse_path_comma_token_tree(db, &tt).nth(derive_index as usize)

diff --git a/crates/hir-expand/src/builtin/derive_macro.rs b/crates/hir-expand/src/builtin/derive_macro.rs
@@ -295,7 +295,7 @@ fn parse_adt_from_syntax(
                             it.syntax(),
                             tm,
                             call_site,
-                            DocCommentDesugarMode::ProcMacro,
+                            DocCommentDesugarMode::Keep,
                         )
                     }
                     None => {
@@ -309,7 +309,7 @@ fn parse_adt_from_syntax(
                         it.syntax(),
                         tm,
                         call_site,
-                        DocCommentDesugarMode::ProcMacro,
+                        DocCommentDesugarMode::Keep,
                     )
                 }),
                 ast::TypeOrConstParam::Const(_) => None,
@@ -322,7 +322,7 @@ fn parse_adt_from_syntax(
                             ty.syntax(),
                             tm,
                             call_site,
-                            DocCommentDesugarMode::ProcMacro,
+                            DocCommentDesugarMode::Keep,
                         )
                     })
                     .unwrap_or_else(|| {
@@ -343,7 +343,7 @@ fn parse_adt_from_syntax(
                     it.syntax(),
                     tm,
                     call_site,
-                    DocCommentDesugarMode::ProcMacro,
+                    DocCommentDesugarMode::Keep,
                 )
             })
             .collect()
@@ -380,7 +380,7 @@ fn parse_adt_from_syntax(
                 it.syntax(),
                 tm,
                 call_site,
-                DocCommentDesugarMode::ProcMacro,
+                DocCommentDesugarMode::Keep,
             )
         })
         .collect();
@@ -664,7 +664,7 @@ fn coerce_shared_target(
         FxHashMap::default(),
         remove,
         span,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
         |_, _| (true, Vec::new()),
     );
 
@@ -1464,7 +1464,7 @@ fn coerce_pointee_expand(
         self_for_traits.syntax(),
         &span_map,
         span,
-        DocCommentDesugarMode::ProcMacro,
+        DocCommentDesugarMode::Keep,
     );
     let info = match parse_adt_from_syntax(&adt, &span_map, span) {
         Ok(it) => it,

diff --git a/crates/hir-expand/src/builtin/fn_macro.rs b/crates/hir-expand/src/builtin/fn_macro.rs
@@ -842,7 +842,7 @@ fn include_expand(
         &editioned_file_id.parse(db).syntax_node(),
         crate::HirFileId::from(editioned_file_id).span_map(db),
         span,
-        syntax_bridge::DocCommentDesugarMode::ProcMacro,
+        syntax_bridge::DocCommentDesugarMode::Keep,
     ))
 }
 

diff --git a/crates/hir-expand/src/cfg_process.rs b/crates/hir-expand/src/cfg_process.rs
@@ -297,18 +297,24 @@ pub(crate) fn attr_macro_input_to_token_tree(
     span_map: SpanMap<'_>,
     span: Span,
     is_derive: bool,
+    is_declarative: bool,
     censor_item_tree_attr_ids: &[AttrId],
     krate: Crate,
 ) -> (tt::TopSubtree, SyntaxFixupUndoInfo) {
-    let fixups = fixup::fixup_syntax(span_map, node, span, DocCommentDesugarMode::ProcMacro);
+    let doc_comment_mode = if is_declarative {
+        DocCommentDesugarMode::DesugarMbeInput
+    } else {
+        DocCommentDesugarMode::Keep
+    };
+    let fixups = fixup::fixup_syntax(span_map, node, span, doc_comment_mode);
     (
         syntax_bridge::syntax_node_to_token_tree_modified(
             node,
             span_map,
             fixups.append,
             fixups.remove,
             span,
-            DocCommentDesugarMode::ProcMacro,
+            doc_comment_mode,
             macro_input_callback(db, is_derive, censor_item_tree_attr_ids, krate, span, span_map),
         ),
         fixups.undo_info,