Auto merge of #97582 - tmiasko:pointer-address-cast, r=oli-obk

Add a pointer to address cast kind

A pointer to address cast are often special-cased. Introduce a dedicated cast kind to make them easy distinguishable.

4 files changed, 9 insertions, 14 deletions

diff --git a/src/test/mir-opt/const_prop/const_prop_fails_gracefully.main.ConstProp.diff b/src/test/mir-opt/const_prop/const_prop_fails_gracefully.main.ConstProp.diff
index 466c286c9d7..4fdd4b2b4bb 100644
--- a/src/test/mir-opt/const_prop/const_prop_fails_gracefully.main.ConstProp.diff
+++ b/src/test/mir-opt/const_prop/const_prop_fails_gracefully.main.ConstProp.diff
@@ -21,7 +21,7 @@
                                            // + span: $DIR/const_prop_fails_gracefully.rs:7:13: 7:16
                                            // + literal: Const { ty: &i32, val: Unevaluated(FOO, [], None) }
           _2 = &raw const (*_3);           // scope 0 at $DIR/const_prop_fails_gracefully.rs:7:13: 7:16
-          _1 = move _2 as usize (Misc);    // scope 0 at $DIR/const_prop_fails_gracefully.rs:7:13: 7:39
+          _1 = move _2 as usize (PointerAddress); // scope 0 at $DIR/const_prop_fails_gracefully.rs:7:13: 7:39
           StorageDead(_2);                 // scope 0 at $DIR/const_prop_fails_gracefully.rs:7:38: 7:39
           StorageDead(_3);                 // scope 0 at $DIR/const_prop_fails_gracefully.rs:7:39: 7:40
           StorageLive(_4);                 // scope 1 at $DIR/const_prop_fails_gracefully.rs:8:5: 8:12
diff --git a/src/test/mir-opt/const_prop/reify_fn_ptr.main.ConstProp.diff b/src/test/mir-opt/const_prop/reify_fn_ptr.main.ConstProp.diff
index 1aeeae91d20..7eb34ed5469 100644
--- a/src/test/mir-opt/const_prop/reify_fn_ptr.main.ConstProp.diff
+++ b/src/test/mir-opt/const_prop/reify_fn_ptr.main.ConstProp.diff
@@ -17,7 +17,7 @@
                                            // mir::Constant
                                            // + span: $DIR/reify_fn_ptr.rs:4:13: 4:17
                                            // + literal: Const { ty: fn() {main}, val: Value(Scalar(<ZST>)) }
-          _2 = move _3 as usize (Misc);    // scope 0 at $DIR/reify_fn_ptr.rs:4:13: 4:26
+          _2 = move _3 as usize (PointerAddress); // scope 0 at $DIR/reify_fn_ptr.rs:4:13: 4:26
           StorageDead(_3);                 // scope 0 at $DIR/reify_fn_ptr.rs:4:25: 4:26
           _1 = move _2 as *const fn() (Misc); // scope 0 at $DIR/reify_fn_ptr.rs:4:13: 4:41
           StorageDead(_2);                 // scope 0 at $DIR/reify_fn_ptr.rs:4:40: 4:41
diff --git a/src/test/mir-opt/dead-store-elimination/provenance_soundness.pointer_to_int.DeadStoreElimination.diff b/src/test/mir-opt/dead-store-elimination/provenance_soundness.pointer_to_int.DeadStoreElimination.diff
index 2250159c816..bf32245e300 100644
--- a/src/test/mir-opt/dead-store-elimination/provenance_soundness.pointer_to_int.DeadStoreElimination.diff
+++ b/src/test/mir-opt/dead-store-elimination/provenance_soundness.pointer_to_int.DeadStoreElimination.diff
@@ -19,12 +19,12 @@
           StorageLive(_2);                 // scope 0 at $DIR/provenance_soundness.rs:8:9: 8:11
           StorageLive(_3);                 // scope 0 at $DIR/provenance_soundness.rs:8:14: 8:15
           _3 = _1;                         // scope 0 at $DIR/provenance_soundness.rs:8:14: 8:15
-          _2 = move _3 as usize (Misc);    // scope 0 at $DIR/provenance_soundness.rs:8:14: 8:24
+          _2 = move _3 as usize (PointerAddress); // scope 0 at $DIR/provenance_soundness.rs:8:14: 8:24
           StorageDead(_3);                 // scope 0 at $DIR/provenance_soundness.rs:8:23: 8:24
           StorageLive(_4);                 // scope 1 at $DIR/provenance_soundness.rs:9:9: 9:11
           StorageLive(_5);                 // scope 1 at $DIR/provenance_soundness.rs:9:14: 9:15
           _5 = _1;                         // scope 1 at $DIR/provenance_soundness.rs:9:14: 9:15
-          _4 = move _5 as isize (Misc);    // scope 1 at $DIR/provenance_soundness.rs:9:14: 9:24
+          _4 = move _5 as isize (PointerAddress); // scope 1 at $DIR/provenance_soundness.rs:9:14: 9:24
           StorageDead(_5);                 // scope 1 at $DIR/provenance_soundness.rs:9:23: 9:24
           _0 = const ();                   // scope 0 at $DIR/provenance_soundness.rs:7:32: 10:2
           StorageDead(_4);                 // scope 1 at $DIR/provenance_soundness.rs:10:1: 10:2
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index 78d8f1e213a..283b20fc24d 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -125,16 +125,11 @@ fn check_rvalue<'tcx>(
         Rvalue::Len(place) | Rvalue::Discriminant(place) | Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
             check_place(tcx, *place, span, body)
         },
-        Rvalue::Cast(CastKind::Misc, operand, cast_ty) => {
-            use rustc_middle::ty::cast::CastTy;
-            let cast_in = CastTy::from_ty(operand.ty(body, tcx)).expect("bad input type for cast");
-            let cast_out = CastTy::from_ty(*cast_ty).expect("bad output type for cast");
-            match (cast_in, cast_out) {
-                (CastTy::Ptr(_) | CastTy::FnPtr, CastTy::Int(_)) => {
-                    Err((span, "casting pointers to ints is unstable in const fn".into()))
-                },
-                _ => check_operand(tcx, operand, span, body),
-            }
+        Rvalue::Cast(CastKind::PointerAddress, _, _) => {
+            Err((span, "casting pointers to ints is unstable in const fn".into()))
+        },
+        Rvalue::Cast(CastKind::Misc, operand, _) => {
+            check_operand(tcx, operand, span, body)
         },
         Rvalue::Cast(CastKind::Pointer(PointerCast::MutToConstPointer | PointerCast::ArrayToPointer), operand, _) => {
             check_operand(tcx, operand, span, body)