Fix the MSRV and add the tests for MSRV

clippy_lints/src/types.rs

@@ -2968,4 +2968,6 @@ impl<'tcx> LateLintPass<'tcx> for PtrAsPtr {
             }
         }
     }
+
+    extract_msrv_attr!(LateContext);
 }

tests/ui/ptr_as_ptr.fixed

@@ -1,6 +1,7 @@
 // run-rustfix
 
 #![warn(clippy::ptr_as_ptr)]
+#![feature(custom_inner_attributes)]
 
 fn main() {
     let ptr: *const u32 = &42_u32;
@@ -28,3 +29,22 @@ fn main() {
     let _: *const i32 = ptr.cast();
     let _: *mut i32 = mut_ptr.cast();
 }
+
+fn _msrv_1_37() {
+    #![clippy::msrv = "1.37"]
+    let ptr: *const u32 = &42_u32;
+    let mut_ptr: *mut u32 = &mut 42_u32;
+
+    // `pointer::cast` was stabilized in 1.38. Do not lint this
+    let _ = ptr as *const i32;
+    let _ = mut_ptr as *mut i32;
+}
+
+fn _msrv_1_38() {
+    #![clippy::msrv = "1.38"]
+    let ptr: *const u32 = &42_u32;
+    let mut_ptr: *mut u32 = &mut 42_u32;
+
+    let _ = ptr.cast::<i32>();
+    let _ = mut_ptr.cast::<i32>();
+}

tests/ui/ptr_as_ptr.rs

@@ -1,6 +1,7 @@
 // run-rustfix
 
 #![warn(clippy::ptr_as_ptr)]
+#![feature(custom_inner_attributes)]
 
 fn main() {
     let ptr: *const u32 = &42_u32;
@@ -28,3 +29,22 @@ fn main() {
     let _: *const i32 = ptr as *const _;
     let _: *mut i32 = mut_ptr as _;
 }
+
+fn _msrv_1_37() {
+    #![clippy::msrv = "1.37"]
+    let ptr: *const u32 = &42_u32;
+    let mut_ptr: *mut u32 = &mut 42_u32;
+
+    // `pointer::cast` was stabilized in 1.38. Do not lint this
+    let _ = ptr as *const i32;
+    let _ = mut_ptr as *mut i32;
+}
+
+fn _msrv_1_38() {
+    #![clippy::msrv = "1.38"]
+    let ptr: *const u32 = &42_u32;
+    let mut_ptr: *mut u32 = &mut 42_u32;
+
+    let _ = ptr as *const i32;
+    let _ = mut_ptr as *mut i32;
+}

tests/ui/ptr_as_ptr.stderr

@@ -1,5 +1,5 @@
 error: `as` casting between raw pointers without changing its mutability
-  --> $DIR/ptr_as_ptr.rs:9:13
+  --> $DIR/ptr_as_ptr.rs:10:13
    |
 LL |     let _ = ptr as *const i32;
    |             ^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `ptr.cast::<i32>()`
@@ -7,28 +7,40 @@ LL |     let _ = ptr as *const i32;
    = note: `-D clippy::ptr-as-ptr` implied by `-D warnings`
 
 error: `as` casting between raw pointers without changing its mutability
-  --> $DIR/ptr_as_ptr.rs:10:13
+  --> $DIR/ptr_as_ptr.rs:11:13
    |
 LL |     let _ = mut_ptr as *mut i32;
    |             ^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `mut_ptr.cast::<i32>()`
 
 error: `as` casting between raw pointers without changing its mutability
-  --> $DIR/ptr_as_ptr.rs:15:17
+  --> $DIR/ptr_as_ptr.rs:16:17
    |
 LL |         let _ = *ptr_ptr as *const i32;
    |                 ^^^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `(*ptr_ptr).cast::<i32>()`
 
 error: `as` casting between raw pointers without changing its mutability
-  --> $DIR/ptr_as_ptr.rs:28:25
+  --> $DIR/ptr_as_ptr.rs:29:25
    |
 LL |     let _: *const i32 = ptr as *const _;
    |                         ^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `ptr.cast()`
 
 error: `as` casting between raw pointers without changing its mutability
-  --> $DIR/ptr_as_ptr.rs:29:23
+  --> $DIR/ptr_as_ptr.rs:30:23
    |
 LL |     let _: *mut i32 = mut_ptr as _;
    |                       ^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `mut_ptr.cast()`
 
-error: aborting due to 5 previous errors
+error: `as` casting between raw pointers without changing its mutability
+  --> $DIR/ptr_as_ptr.rs:48:13
+   |
+LL |     let _ = ptr as *const i32;
+   |             ^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `ptr.cast::<i32>()`
+
+error: `as` casting between raw pointers without changing its mutability
+  --> $DIR/ptr_as_ptr.rs:49:13
+   |
+LL |     let _ = mut_ptr as *mut i32;
+   |             ^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast`, a safer alternative: `mut_ptr.cast::<i32>()`
+
+error: aborting due to 7 previous errors