From b17a3e2f2dd8f9121e13bbaf0428df6be5162062 Mon Sep 17 00:00:00 2001
From: lapla <me@lapla.dev>
Date: Wed, 15 Apr 2026 00:33:36 +0900
Subject: [PATCH] Fix misleading "borrowed data escapes outside of function"
 diagnostic

---
 .../rustc_borrowck/src/diagnostics/region_errors.rs    |  2 ++
 .../fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs    |  8 ++++++++
 ...fn-ptr-lifetime-mismatch-with-impl-trait-arg.stderr | 10 ++++++++++
 3 files changed, 20 insertions(+)
 create mode 100644 tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs
 create mode 100644 tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.stderr

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index f6a20e41742b..934eadd215ad 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -686,6 +686,8 @@ fn report_escaping_data_error(&self, errci: &ErrorConstraintInfo<'tcx>) -> Diag<
             || (*category == ConstraintCategory::Assignment
                 && self.regioncx.universal_regions().defining_ty.is_fn_def())
             || self.regioncx.universal_regions().defining_ty.is_const()
+            || (fr_name_and_span.is_none()
+                && self.regioncx.universal_regions().defining_ty.is_fn_def())
         {
             return self.report_general_error(errci);
         }
diff --git a/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs b/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs
new file mode 100644
index 000000000000..730e5cdc278f
--- /dev/null
+++ b/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs
@@ -0,0 +1,8 @@
+// Regression test for https://github.com/rust-lang/rust/issues/154350
+
+fn func<'a>(f: impl FnOnce(fn(&'a i32)), x: fn(&'static i32)) {
+    f(x);
+    //~^ ERROR lifetime may not live long enough
+}
+
+fn main() {}
diff --git a/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.stderr b/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.stderr
new file mode 100644
index 000000000000..92c613acdd83
--- /dev/null
+++ b/tests/ui/borrowck/fn-ptr-lifetime-mismatch-with-impl-trait-arg.stderr
@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/fn-ptr-lifetime-mismatch-with-impl-trait-arg.rs:4:5
+   |
+LL | fn func<'a>(f: impl FnOnce(fn(&'a i32)), x: fn(&'static i32)) {
+   |         -- lifetime `'a` defined here
+LL |     f(x);
+   |     ^^^^ argument requires that `'a` must outlive `'static`
+
+error: aborting due to 1 previous error
+