From 0cb6a51776e72b702aedbb55e862a60d193e740a Mon Sep 17 00:00:00 2001
From: Samuel Tardieu <sam@rfc1149.net>
Date: Wed, 25 Jun 2025 16:57:11 +0200
Subject: [PATCH] `unsafe_derive_deserialize`: do not consider `pin!()` as
 `unsafe`

In Rust 1.88, the `pin!()` macro uses `unsafe` and triggers
`unsafe_derive_deserialize`.
---
 clippy_lints/src/derive.rs            |  7 +++++++
 tests/ui/unsafe_derive_deserialize.rs | 12 ++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/clippy_lints/src/derive.rs b/clippy_lints/src/derive.rs
index 062f7cef3a72..ea8df9faa213 100644
--- a/clippy_lints/src/derive.rs
+++ b/clippy_lints/src/derive.rs
@@ -432,6 +432,13 @@ impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx Expr<'_>) -> Self::Result {
         if let ExprKind::Block(block, _) = expr.kind
             && block.rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided)
+            && block
+                .span
+                .source_callee()
+                .and_then(|expr| expr.macro_def_id)
+                .is_none_or(|did| {
+                    (self.cx.tcx.crate_name(did.krate), self.cx.tcx.item_name(did)) != (sym::core, sym::pin)
+                })
         {
             return ControlFlow::Break(());
         }
diff --git a/tests/ui/unsafe_derive_deserialize.rs b/tests/ui/unsafe_derive_deserialize.rs
index 14371bc203b3..4f11030e9c8d 100644
--- a/tests/ui/unsafe_derive_deserialize.rs
+++ b/tests/ui/unsafe_derive_deserialize.rs
@@ -82,3 +82,15 @@ impl H {
 }
 
 fn main() {}
+
+mod issue15120 {
+    #[derive(serde::Deserialize)]
+    struct Foo;
+
+    impl Foo {
+        fn foo(&self) {
+            // Do not lint if `unsafe` comes from the `core::pin::pin!()` macro
+            std::pin::pin!(());
+        }
+    }
+}