From 7ff6be61e1a1f3b86feca44dcb7096ac16926ba7 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <contact@guillaume-gomez.fr>
Date: Thu, 27 Aug 2026 17:52:02 +0200
Subject: [PATCH 1/2] rustdoc: Correctly handle when a macro generates multiple
 items in `--generate-macro-expansion`

---
 src/librustdoc/html/macro_expansion.rs        |  9 +++++++-
 .../multiple-items-in-one-macro-call.rs       | 22 +++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 tests/rustdoc-html/macro-expansion/multiple-items-in-one-macro-call.rs

diff --git a/src/librustdoc/html/macro_expansion.rs b/src/librustdoc/html/macro_expansion.rs
index 4c820415e273c..9688a9e3fd7cf 100644
--- a/src/librustdoc/html/macro_expansion.rs
+++ b/src/librustdoc/html/macro_expansion.rs
@@ -46,6 +46,7 @@ pub(crate) struct ExpandedCode {
 /// As we go through the HIR visitor, if any span overlaps with another, they will
 /// both be merged.
 struct ExpandedCodeInfo {
+    original_span: Span,
     /// Callsite of the macro.
     span: Span,
     /// Expanded macro source code (HTML escaped).
@@ -73,7 +74,12 @@ impl<'ast> ExpandedCodeVisitor<'ast> {
             self.expanded_codes.iter().position(|info| info.span.overlaps(callsite_span))
         {
             let info = &mut self.expanded_codes[index];
-            if new_span.contains(info.expanded_span) {
+            // If the new span we got has the exact same span information as a span already in the
+            // list, it means it's generated from the same macro but is a different item, so we need
+            // to add it as well.
+            let has_same_macro_origin =
+                new_span == info.original_span && callsite_span == info.span;
+            if !has_same_macro_origin && new_span.contains(info.expanded_span) {
                 // New macro expansion recursively contains the old one, so replace it.
                 info.span = callsite_span;
                 info.expanded_span = new_span;
@@ -90,6 +96,7 @@ impl<'ast> ExpandedCodeVisitor<'ast> {
         } else {
             // We add a new item.
             self.expanded_codes.push(ExpandedCodeInfo {
+                original_span: new_span,
                 span: callsite_span,
                 code: f(),
                 expanded_span: new_span,
diff --git a/tests/rustdoc-html/macro-expansion/multiple-items-in-one-macro-call.rs b/tests/rustdoc-html/macro-expansion/multiple-items-in-one-macro-call.rs
new file mode 100644
index 0000000000000..782500db9d581
--- /dev/null
+++ b/tests/rustdoc-html/macro-expansion/multiple-items-in-one-macro-call.rs
@@ -0,0 +1,22 @@
+// This test ensures that when a macro call expands to multiple items,
+// all of them are present in the macro expansion.
+// Regression test for <https://github.com/rust-lang/rust/issues/157508>.
+
+//@ compile-flags: -Zunstable-options --generate-macro-expansion
+
+#![crate_name = "foo"]
+
+macro_rules! print_skip {
+    ($($t: ty),* $(,)?) => {$
+        (impl $t { fn f() {} })*
+    };
+}
+
+pub struct A;
+pub struct B;
+
+//@ has 'src/foo/multiple-items-in-one-macro-call.rs.html'
+// Both `impl A` and `impl B` should be here.
+//@ matches - '//*[@class="expansion"]/*[@class="expanded"]' \
+//    '^impl A \{\s+fn f\(\) \{\}\n\}\nimpl B \{\s+fn f\(\) \{\}\n\}$'
+print_skip!(A, B);

From c9cb963e080b5e3239789808356eb970cfa1e0fa Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <contact@guillaume-gomez.fr>
Date: Thu, 27 Aug 2026 20:56:16 +0200
Subject: [PATCH 2/2] Fix incorrect `hi` Span bound in rustdoc macro expansion

---
 src/librustdoc/html/macro_expansion.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustdoc/html/macro_expansion.rs b/src/librustdoc/html/macro_expansion.rs
index 9688a9e3fd7cf..55ca93e601b70 100644
--- a/src/librustdoc/html/macro_expansion.rs
+++ b/src/librustdoc/html/macro_expansion.rs
@@ -90,7 +90,7 @@ impl<'ast> ExpandedCodeVisitor<'ast> {
                 expanded_code.code.push('\n');
                 expanded_code.code.push_str(&f());
                 let lo = BytePos(expanded_code.expanded_span.lo().0.min(new_span.lo().0));
-                let hi = BytePos(expanded_code.expanded_span.hi().0.min(new_span.hi().0));
+                let hi = BytePos(expanded_code.expanded_span.hi().0.max(new_span.hi().0));
                 expanded_code.expanded_span = expanded_code.expanded_span.with_lo(lo).with_hi(hi);
             }
         } else {