ptr_as_ptr: fix incorrect suggestion with `pointer::cast` and macros (#15514)

Fixes https://github.com/rust-lang/rust-clippy/issues/15232

changelog: [`ptr_as_ptr`]: fix incorrect suggestion with `pointer::cast`
and macros

3 files changed, 19 insertions, 1 deletions

diff --git a/tests/ui/ptr_as_ptr.fixed b/tests/ui/ptr_as_ptr.fixed
index 78e1ceb480a..4457878b6fa 100644
--- a/tests/ui/ptr_as_ptr.fixed
+++ b/tests/ui/ptr_as_ptr.fixed
@@ -229,3 +229,9 @@ fn issue15283() {
         //~^ ptr_as_ptr
     }
 }
+
+fn issue15232() {
+    let mut b = Box::new(0i32);
+    let _ptr = std::ptr::addr_of_mut!(*b).cast::<()>();
+    //~^ ptr_as_ptr
+}
diff --git a/tests/ui/ptr_as_ptr.rs b/tests/ui/ptr_as_ptr.rs
index 70732cf0a6c..9124fc912d2 100644
--- a/tests/ui/ptr_as_ptr.rs
+++ b/tests/ui/ptr_as_ptr.rs
@@ -229,3 +229,9 @@ fn issue15283() {
         //~^ ptr_as_ptr
     }
 }
+
+fn issue15232() {
+    let mut b = Box::new(0i32);
+    let _ptr = std::ptr::addr_of_mut!(*b) as *mut ();
+    //~^ ptr_as_ptr
+}
diff --git a/tests/ui/ptr_as_ptr.stderr b/tests/ui/ptr_as_ptr.stderr
index c0a2a4b6d20..af21c1e35f5 100644
--- a/tests/ui/ptr_as_ptr.stderr
+++ b/tests/ui/ptr_as_ptr.stderr
@@ -199,5 +199,11 @@ error: `as` casting between raw pointers without changing their constness
 LL |         let _: fn() = std::mem::transmute(std::ptr::null::<()>() as *const u8);
    |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try call directly: `std::ptr::null::<u8>()`
 
-error: aborting due to 33 previous errors
+error: `as` casting between raw pointers without changing their constness
+  --> tests/ui/ptr_as_ptr.rs:235:16
+   |
+LL |     let _ptr = std::ptr::addr_of_mut!(*b) as *mut ();
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `std::ptr::addr_of_mut!(*b).cast::<()>()`
+
+error: aborting due to 34 previous errors