From dfcfd73b2c3bc0c076226ebbb04554b689dd5041 Mon Sep 17 00:00:00 2001
From: linshuy2 <linshuy2@illinois.edu>
Date: Mon, 26 Jan 2026 17:57:34 +0000
Subject: [PATCH] fix: `cmp_owned` FP when `to_string` comes from macro input

---
 clippy_lints/src/operators/cmp_owned.rs   | 12 ++++++---
 clippy_lints/src/operators/mod.rs         |  2 +-
 tests/ui/cmp_owned/with_suggestion.fixed  | 32 +++++++++++++++++++++++
 tests/ui/cmp_owned/with_suggestion.rs     | 32 +++++++++++++++++++++++
 tests/ui/cmp_owned/with_suggestion.stderr | 15 ++++++++++-
 5 files changed, 87 insertions(+), 6 deletions(-)

diff --git a/clippy_lints/src/operators/cmp_owned.rs b/clippy_lints/src/operators/cmp_owned.rs
index 39097833a6c5..db55772f4e01 100644
--- a/clippy_lints/src/operators/cmp_owned.rs
+++ b/clippy_lints/src/operators/cmp_owned.rs
@@ -10,10 +10,10 @@
 
 use super::CMP_OWNED;
 
-pub(super) fn check(cx: &LateContext<'_>, op: BinOpKind, lhs: &Expr<'_>, rhs: &Expr<'_>) {
+pub(super) fn check(cx: &LateContext<'_>, e: &Expr<'_>, op: BinOpKind, lhs: &Expr<'_>, rhs: &Expr<'_>) {
     if op.is_comparison() {
-        check_op(cx, lhs, rhs, true);
-        check_op(cx, rhs, lhs, false);
+        check_op(cx, e, lhs, rhs, true);
+        check_op(cx, e, rhs, lhs, false);
     }
 }
 
@@ -35,7 +35,11 @@ fn symmetric_partial_eq<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, other: Ty<'t
     })
 }
 
-fn check_op(cx: &LateContext<'_>, expr: &Expr<'_>, other: &Expr<'_>, left: bool) {
+fn check_op(cx: &LateContext<'_>, outer: &Expr<'_>, expr: &Expr<'_>, other: &Expr<'_>, left: bool) {
+    if !outer.span.eq_ctxt(expr.span) {
+        return;
+    }
+
     let typeck = cx.typeck_results();
     let (arg, arg_span) = match expr.kind {
         ExprKind::MethodCall(_, arg, [], _)
diff --git a/clippy_lints/src/operators/mod.rs b/clippy_lints/src/operators/mod.rs
index 53b8e9e5d5ae..383b135dfa50 100644
--- a/clippy_lints/src/operators/mod.rs
+++ b/clippy_lints/src/operators/mod.rs
@@ -1038,7 +1038,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
                 float_equality_without_abs::check(cx, e, op.node, lhs, rhs);
                 integer_division::check(cx, e, op.node, lhs, rhs);
                 integer_division_remainder_used::check(cx, op.node, lhs, rhs, e.span);
-                cmp_owned::check(cx, op.node, lhs, rhs);
+                cmp_owned::check(cx, e, op.node, lhs, rhs);
                 float_cmp::check(cx, e, op.node, lhs, rhs);
                 modulo_one::check(cx, e, op.node, rhs);
                 modulo_arithmetic::check(
diff --git a/tests/ui/cmp_owned/with_suggestion.fixed b/tests/ui/cmp_owned/with_suggestion.fixed
index 4c3b13b30043..f65339605e75 100644
--- a/tests/ui/cmp_owned/with_suggestion.fixed
+++ b/tests/ui/cmp_owned/with_suggestion.fixed
@@ -112,3 +112,35 @@ fn issue16322(item: String) {
         println!("Ja!");
     }
 }
+
+fn issue16458() {
+    macro_rules! partly_comes_from_macro {
+        ($i:ident: $ty:ty, $def:expr) => {
+            let _ = {
+                let res = <$ty>::default() == $def;
+                let _i: $ty = $def;
+                res
+            };
+        };
+    }
+
+    partly_comes_from_macro! {
+        required_version: String, env!("HOME").to_string()
+    }
+
+    macro_rules! all_comes_from_macro {
+        ($($i:ident: $ty:ty, $def:expr);+ $(;)*) => {
+            $(
+                let _ = {
+                    let res = <$ty>::default() == "$def";
+                    //~^ cmp_owned
+                    let _i: $ty = $def;
+                    res
+                };
+            )+
+        };
+    }
+    all_comes_from_macro! {
+        required_version: String, env!("HOME").to_string();
+    }
+}
diff --git a/tests/ui/cmp_owned/with_suggestion.rs b/tests/ui/cmp_owned/with_suggestion.rs
index a9d7509feaaf..ed2300c80eaa 100644
--- a/tests/ui/cmp_owned/with_suggestion.rs
+++ b/tests/ui/cmp_owned/with_suggestion.rs
@@ -112,3 +112,35 @@ fn issue16322(item: String) {
         println!("Ja!");
     }
 }
+
+fn issue16458() {
+    macro_rules! partly_comes_from_macro {
+        ($i:ident: $ty:ty, $def:expr) => {
+            let _ = {
+                let res = <$ty>::default() == $def;
+                let _i: $ty = $def;
+                res
+            };
+        };
+    }
+
+    partly_comes_from_macro! {
+        required_version: String, env!("HOME").to_string()
+    }
+
+    macro_rules! all_comes_from_macro {
+        ($($i:ident: $ty:ty, $def:expr);+ $(;)*) => {
+            $(
+                let _ = {
+                    let res = <$ty>::default() == "$def".to_string();
+                    //~^ cmp_owned
+                    let _i: $ty = $def;
+                    res
+                };
+            )+
+        };
+    }
+    all_comes_from_macro! {
+        required_version: String, env!("HOME").to_string();
+    }
+}
diff --git a/tests/ui/cmp_owned/with_suggestion.stderr b/tests/ui/cmp_owned/with_suggestion.stderr
index 66544ce0c217..38d124baa4b5 100644
--- a/tests/ui/cmp_owned/with_suggestion.stderr
+++ b/tests/ui/cmp_owned/with_suggestion.stderr
@@ -55,5 +55,18 @@ error: this creates an owned instance just for comparison
 LL |     if item == t!(frohes_neu_Jahr).to_string() {
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `t!(frohes_neu_Jahr)`
 
-error: aborting due to 9 previous errors
+error: this creates an owned instance just for comparison
+  --> tests/ui/cmp_owned/with_suggestion.rs:135:51
+   |
+LL |                       let res = <$ty>::default() == "$def".to_string();
+   |                                                     ^^^^^^^^^^^^^^^^^^ help: try: `"$def"`
+...
+LL | /     all_comes_from_macro! {
+LL | |         required_version: String, env!("HOME").to_string();
+LL | |     }
+   | |_____- in this macro invocation
+   |
+   = note: this error originates in the macro `all_comes_from_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 10 previous errors