From 911c305e6f6c10fc01403d62a456bf34fbbf901b Mon Sep 17 00:00:00 2001
From: Thomas Van Strydonck <thomas.vanstrydonck@fortanix.com>
Date: Mon, 18 Aug 2025 20:04:27 +0200
Subject: [PATCH 1/2] fix: `impl Trait` inside macro parsed incorrectly

---
 src/parse/macros/mod.rs    | 14 +++++++-------
 tests/source/issue-6036.rs | 14 ++++++++++++++
 tests/target/issue-6036.rs | 22 ++++++++++++++++++++++
 3 files changed, 43 insertions(+), 7 deletions(-)
 create mode 100644 tests/source/issue-6036.rs
 create mode 100644 tests/target/issue-6036.rs

diff --git a/src/parse/macros/mod.rs b/src/parse/macros/mod.rs
index 8a956faf03b..2c38a20e898 100644
--- a/src/parse/macros/mod.rs
+++ b/src/parse/macros/mod.rs
@@ -52,6 +52,13 @@ fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
         |parser: &mut Parser<'b>| parser.parse_expr(),
         |x: ptr::P<ast::Expr>| Some(x)
     );
+    // `parse_item` returns `Option<ptr::P<ast::Item>>`.
+    parse_macro_arg!(
+        Item,
+        NonterminalKind::Item,
+        |parser: &mut Parser<'b>| parser.parse_item(ForceCollect::No),
+        |x: Option<ptr::P<ast::Item>>| x
+    );
     parse_macro_arg!(
         Ty,
         NonterminalKind::Ty,
@@ -64,13 +71,6 @@ fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
         |parser: &mut Parser<'b>| parser.parse_pat_no_top_alt(None, None),
         |x: ptr::P<ast::Pat>| Some(x)
     );
-    // `parse_item` returns `Option<ptr::P<ast::Item>>`.
-    parse_macro_arg!(
-        Item,
-        NonterminalKind::Item,
-        |parser: &mut Parser<'b>| parser.parse_item(ForceCollect::No),
-        |x: Option<ptr::P<ast::Item>>| x
-    );
 
     None
 }
diff --git a/tests/source/issue-6036.rs b/tests/source/issue-6036.rs
new file mode 100644
index 00000000000..f26d2e784f2
--- /dev/null
+++ b/tests/source/issue-6036.rs
@@ -0,0 +1,14 @@
+fmt_me!(
+impl Foo { fn f(&self) {} }
+);
+fmt_me!(
+impl Bar for Baz { fn m(&self) {} }
+);
+
+// does get formatted
+fmt_me!(
+impl<T> Foo<T> { fn g(&self) {} }
+mod test {
+impl Foo { fn f(&self) {} }
+}
+);
diff --git a/tests/target/issue-6036.rs b/tests/target/issue-6036.rs
new file mode 100644
index 00000000000..9f911770d4e
--- /dev/null
+++ b/tests/target/issue-6036.rs
@@ -0,0 +1,22 @@
+fmt_me!(
+    impl Foo {
+        fn f(&self) {}
+    }
+);
+fmt_me!(
+    impl Bar for Baz {
+        fn m(&self) {}
+    }
+);
+
+// does get formatted
+fmt_me!(
+    impl<T> Foo<T> {
+        fn g(&self) {}
+    }
+    mod test {
+        impl Foo {
+            fn f(&self) {}
+        }
+    }
+);

From de1cf14fecf4b3b3e69377907d6003f244cca5de Mon Sep 17 00:00:00 2001
From: Thomas Van Strydonck <thomas.vanstrydonck@fortanix.com>
Date: Tue, 19 Aug 2025 10:25:43 +0200
Subject: [PATCH 2/2] fix: don't return when `parse_item` returns `None`

---
 src/parse/macros/mod.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/parse/macros/mod.rs b/src/parse/macros/mod.rs
index 2c38a20e898..54e478b86e0 100644
--- a/src/parse/macros/mod.rs
+++ b/src/parse/macros/mod.rs
@@ -29,12 +29,13 @@ fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
             if Parser::nonterminal_may_begin_with($nt_kind, &cloned_parser.token) {
                 match $try_parse(&mut cloned_parser) {
                     Ok(x) => {
-                        if parser.psess.dcx().has_errors().is_some() {
+                        let maybe_parsed = $then(x);
+                        if parser.psess.dcx().has_errors().is_some() || maybe_parsed.is_none() {
                             parser.psess.dcx().reset_err_count();
                         } else {
                             // Parsing succeeded.
                             *parser = cloned_parser;
-                            return Some(MacroArg::$macro_arg($then(x)?));
+                            return Some(MacroArg::$macro_arg(maybe_parsed?));
                         }
                     }
                     Err(e) => {