clippy: avoid invalid ref_as_ptr suggestions in const/static initializers

clippy_lints/src/casts/ref_as_ptr.rs

@@ -1,7 +1,9 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
-use clippy_utils::{ExprUseNode, get_expr_use_site, is_expr_temporary_value, std_or_core};
+use clippy_utils::{
+    ExprUseNode, get_expr_use_site, is_expr_temporary_value, is_inside_always_const_context, std_or_core,
+};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, Mutability, Ty, TyKind};
 use rustc_lint::LateContext;
@@ -26,10 +28,10 @@ pub(super) fn check<'tcx>(
     {
         if let ExprKind::AddrOf(_, _, addr_inner) = cast_expr.kind
             && is_expr_temporary_value(cx, addr_inner)
-            && matches!(
+            && (matches!(
                 get_expr_use_site(cx.tcx, cx.typeck_results(), expr.span.ctxt(), expr).use_node(cx),
                 ExprUseNode::LetStmt(_) | ExprUseNode::ConstStatic(_)
-            )
+            ) || is_inside_always_const_context(cx.tcx, expr.hir_id))
         {
             return;
         }

tests/ui/ref_as_ptr.fixed

@@ -99,6 +99,11 @@ fn main() {
     let _ = &String::new() as *const _;
     let _ = &mut String::new() as *mut _;
     const FOO: *const String = &String::new() as *const _;
+
+    // Regression test for #13910.
+    // This should not lint because the suggested replacement fails during
+    // const evaluation.
+    static mut REGRESSION: *mut i32 = &mut [42] as *mut [i32] as *mut i32;
 }
 
 #[clippy::msrv = "1.75"]

tests/ui/ref_as_ptr.rs

@@ -99,6 +99,11 @@ fn main() {
     let _ = &String::new() as *const _;
     let _ = &mut String::new() as *mut _;
     const FOO: *const String = &String::new() as *const _;
+
+    // Regression test for #13910.
+    // This should not lint because the suggested replacement fails during
+    // const evaluation.
+    static mut REGRESSION: *mut i32 = &mut [42] as *mut [i32] as *mut i32;
 }
 
 #[clippy::msrv = "1.75"]

tests/ui/ref_as_ptr.stderr

@@ -218,67 +218,67 @@ LL |     let _ = &*x as *const _;
    |             ^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(&*x)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:119:7
+  --> tests/ui/ref_as_ptr.rs:124:7
    |
 LL |     f(val as *const i32);
    |       ^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref::<i32>(val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:121:7
+  --> tests/ui/ref_as_ptr.rs:126:7
    |
 LL |     f(mut_val as *mut i32);
    |       ^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_mut::<i32>(mut_val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:126:7
+  --> tests/ui/ref_as_ptr.rs:131:7
    |
 LL |     f(val as *const _);
    |       ^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:128:7
+  --> tests/ui/ref_as_ptr.rs:133:7
    |
 LL |     f(val as *const [u8]);
    |       ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref::<[u8]>(val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:133:7
+  --> tests/ui/ref_as_ptr.rs:138:7
    |
 LL |     f(val as *mut _);
    |       ^^^^^^^^^^^^^ help: try: `std::ptr::from_mut(val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:135:7
+  --> tests/ui/ref_as_ptr.rs:140:7
    |
 LL |     f(val as *mut str);
    |       ^^^^^^^^^^^^^^^ help: try: `std::ptr::from_mut::<str>(val)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:143:9
+  --> tests/ui/ref_as_ptr.rs:148:9
    |
 LL |         self.0 as *const _ as *const _
    |         ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(self.0)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:148:9
+  --> tests/ui/ref_as_ptr.rs:153:9
    |
 LL |         self.0 as *const _ as *const _
    |         ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(self.0)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:157:9
+  --> tests/ui/ref_as_ptr.rs:162:9
    |
 LL |         self.0 as *const _ as *const _
    |         ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(self.0)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:162:9
+  --> tests/ui/ref_as_ptr.rs:167:9
    |
 LL |         self.0 as *const _ as *const _
    |         ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_ref(self.0)`
 
 error: reference as raw pointer
-  --> tests/ui/ref_as_ptr.rs:167:9
+  --> tests/ui/ref_as_ptr.rs:172:9
    |
 LL |         self.0 as *mut _ as *mut _
    |         ^^^^^^^^^^^^^^^^ help: try: `std::ptr::from_mut(self.0)`