From d3ca65d04a88c48665b07c83d03ee1fd0249dbc9 Mon Sep 17 00:00:00 2001
From: Linshu Yang <linshuy2@illinois.edu>
Date: Mon, 5 Jan 2026 17:58:10 +0000
Subject: [PATCH] fix: `manual_rotate` wrongly unmangled macros

---
 clippy_lints/src/manual_rotate.rs | 22 ++++++++++++++--------
 tests/ui/manual_rotate.fixed      | 23 +++++++++++++++++++++++
 tests/ui/manual_rotate.rs         | 23 +++++++++++++++++++++++
 tests/ui/manual_rotate.stderr     | 14 +++++++++++++-
 4 files changed, 73 insertions(+), 9 deletions(-)

diff --git a/clippy_lints/src/manual_rotate.rs b/clippy_lints/src/manual_rotate.rs
index e8db44698d9c..c371e5b47df8 100644
--- a/clippy_lints/src/manual_rotate.rs
+++ b/clippy_lints/src/manual_rotate.rs
@@ -1,7 +1,7 @@
 use std::fmt::Display;
 
 use clippy_utils::consts::{ConstEvalCtxt, Constant};
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::sugg;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind};
@@ -116,17 +116,23 @@ fn check_expr<'tcx>(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) {
                 }
             };
 
-            let mut applicability = Applicability::MachineApplicable;
-            let expr_sugg = sugg::Sugg::hir_with_applicability(cx, l_expr, "_", &mut applicability).maybe_paren();
-            let amount = sugg::Sugg::hir_with_applicability(cx, amount, "_", &mut applicability);
-            span_lint_and_sugg(
+            span_lint_and_then(
                 cx,
                 MANUAL_ROTATE,
                 expr.span,
                 "there is no need to manually implement bit rotation",
-                "this expression can be rewritten as",
-                format!("{expr_sugg}.{shift_function}({amount})"),
-                Applicability::MachineApplicable,
+                |diag| {
+                    let mut applicability = Applicability::MachineApplicable;
+                    let expr_sugg = sugg::Sugg::hir_with_context(cx, l_expr, expr.span.ctxt(), "_", &mut applicability)
+                        .maybe_paren();
+                    let amount = sugg::Sugg::hir_with_context(cx, amount, expr.span.ctxt(), "_", &mut applicability);
+                    diag.span_suggestion(
+                        expr.span,
+                        "this expression can be rewritten as",
+                        format!("{expr_sugg}.{shift_function}({amount})"),
+                        applicability,
+                    );
+                },
             );
         }
     }
diff --git a/tests/ui/manual_rotate.fixed b/tests/ui/manual_rotate.fixed
index 1012ffc1aa2d..17fb4a3122f3 100644
--- a/tests/ui/manual_rotate.fixed
+++ b/tests/ui/manual_rotate.fixed
@@ -61,3 +61,26 @@ fn issue13028() {
     // don't lint, because `s` and `u` are different variables, albeit with the same value
     let _ = (x << s) | (x >> (32 - u));
 }
+
+fn wrongly_unmangled_macros() {
+    macro_rules! test_expr {
+        ($val:expr) => {
+            $val.inner
+        };
+    }
+
+    struct Wrapper {
+        inner: u32,
+    }
+
+    let x = Wrapper { inner: 42 };
+    let _ = test_expr!(x).rotate_left(3);
+    //~^ manual_rotate
+
+    let y = Wrapper { inner: 100 };
+
+    let _ = x.inner.rotate_left(test_expr!(y));
+    //~^ manual_rotate
+
+    let _ = (test_expr!(x) << 3) | (x.inner >> 29);
+}
diff --git a/tests/ui/manual_rotate.rs b/tests/ui/manual_rotate.rs
index 3cdc79673c81..5899166f51f7 100644
--- a/tests/ui/manual_rotate.rs
+++ b/tests/ui/manual_rotate.rs
@@ -61,3 +61,26 @@ fn issue13028() {
     // don't lint, because `s` and `u` are different variables, albeit with the same value
     let _ = (x << s) | (x >> (32 - u));
 }
+
+fn wrongly_unmangled_macros() {
+    macro_rules! test_expr {
+        ($val:expr) => {
+            $val.inner
+        };
+    }
+
+    struct Wrapper {
+        inner: u32,
+    }
+
+    let x = Wrapper { inner: 42 };
+    let _ = (test_expr!(x) << 3) | (test_expr!(x) >> 29);
+    //~^ manual_rotate
+
+    let y = Wrapper { inner: 100 };
+
+    let _ = (x.inner << test_expr!(y)) | (x.inner >> (32 - test_expr!(y)));
+    //~^ manual_rotate
+
+    let _ = (test_expr!(x) << 3) | (x.inner >> 29);
+}
diff --git a/tests/ui/manual_rotate.stderr b/tests/ui/manual_rotate.stderr
index ea04ee028db6..76af443ae89e 100644
--- a/tests/ui/manual_rotate.stderr
+++ b/tests/ui/manual_rotate.stderr
@@ -91,5 +91,17 @@ error: there is no need to manually implement bit rotation
 LL |     let _ = (x >> 9) | (x << (32 - 9));
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: this expression can be rewritten as: `x.rotate_right(9)`
 
-error: aborting due to 15 previous errors
+error: there is no need to manually implement bit rotation
+  --> tests/ui/manual_rotate.rs:77:13
+   |
+LL |     let _ = (test_expr!(x) << 3) | (test_expr!(x) >> 29);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: this expression can be rewritten as: `test_expr!(x).rotate_left(3)`
+
+error: there is no need to manually implement bit rotation
+  --> tests/ui/manual_rotate.rs:82:13
+   |
+LL |     let _ = (x.inner << test_expr!(y)) | (x.inner >> (32 - test_expr!(y)));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: this expression can be rewritten as: `x.inner.rotate_left(test_expr!(y))`
+
+error: aborting due to 17 previous errors