[borrow_as_ptr]: Ignore temporaries

clippy_lints/src/casts/borrow_as_ptr.rs

@@ -4,6 +4,7 @@ use clippy_utils::source::snippet_with_context;
 use rustc_errors::Applicability;
 use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, Ty, TyKind};
 use rustc_lint::LateContext;
+use rustc_middle::ty::adjustment::Adjust;
 
 use super::BORROW_AS_PTR;
 
@@ -23,6 +24,15 @@ pub(super) fn check<'tcx>(
         };
         let mut app = Applicability::MachineApplicable;
         let snip = snippet_with_context(cx, e.span, cast_expr.span.ctxt(), "..", &mut app).0;
+        // Fix #9884
+        if !e.is_place_expr(|base| {
+            cx.typeck_results()
+                .adjustments()
+                .get(base.hir_id)
+                .is_some_and(|x| x.iter().any(|adj| matches!(adj.kind, Adjust::Deref(_))))
+        }) {
+            return;
+        }
 
         span_lint_and_sugg(
             cx,

tests/ui/borrow_as_ptr.fixed

@@ -1,9 +1,18 @@
 //@run-rustfix
 #![warn(clippy::borrow_as_ptr)]
+#![allow(clippy::useless_vec)]
+
+fn a() -> i32 {
+    0
+}
 
 fn main() {
     let val = 1;
     let _p = std::ptr::addr_of!(val);
+    let _p = &0 as *const i32;
+    let _p = &a() as *const i32;
+    let vec = vec![1];
+    let _p = &vec.len() as *const usize;
 
     let mut val_mut = 1;
     let _p_mut = std::ptr::addr_of_mut!(val_mut);

tests/ui/borrow_as_ptr.rs

@@ -1,9 +1,18 @@
 //@run-rustfix
 #![warn(clippy::borrow_as_ptr)]
+#![allow(clippy::useless_vec)]
+
+fn a() -> i32 {
+    0
+}
 
 fn main() {
     let val = 1;
     let _p = &val as *const i32;
+    let _p = &0 as *const i32;
+    let _p = &a() as *const i32;
+    let vec = vec![1];
+    let _p = &vec.len() as *const usize;
 
     let mut val_mut = 1;
     let _p_mut = &mut val_mut as *mut i32;

tests/ui/borrow_as_ptr.stderr

@@ -1,13 +1,13 @@
 error: borrow as raw pointer
-  --> $DIR/borrow_as_ptr.rs:6:14
+  --> $DIR/borrow_as_ptr.rs:11:14
    |
 LL |     let _p = &val as *const i32;
    |              ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::addr_of!(val)`
    |
    = note: `-D clippy::borrow-as-ptr` implied by `-D warnings`
 
 error: borrow as raw pointer
-  --> $DIR/borrow_as_ptr.rs:9:18
+  --> $DIR/borrow_as_ptr.rs:18:18
    |
 LL |     let _p_mut = &mut val_mut as *mut i32;
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::addr_of_mut!(val_mut)`