1 files changed, 88 insertions, 34 deletions
diff --git a/tests/ui/lint/reference_casting.rs b/tests/ui/lint/reference_casting.rs
index 996382049..6c38bca3d 100644
--- a/tests/ui/lint/reference_casting.rs
+++ b/tests/ui/lint/reference_casting.rs
@@ -1,7 +1,6 @@
 // check-fail
 
 #![feature(ptr_from_ref)]
-#![deny(invalid_reference_casting)]
 
 extern "C" {
     // N.B., mutability can be easily incorrect in FFI calls -- as
@@ -10,42 +9,97 @@ extern "C" {
     fn int_ffi(c: *mut i32);
 }
 
-fn main() {
+fn static_u8() -> &'static u8 {
+    &8
+}
+
+unsafe fn ref_to_mut() {
+    let num = &3i32;
+
+    let _num = &mut *(num as *const i32 as *mut i32);
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(num as *const i32).cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *std::ptr::from_ref(num).cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *std::ptr::from_ref({ num }).cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *{ std::ptr::from_ref(num) }.cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(std::ptr::from_ref({ num }) as *mut i32);
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(num as *const i32).cast::<i32>().cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(num as *const i32).cast::<i32>().cast_mut().cast_const().cast_mut();
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(std::ptr::from_ref(static_u8()) as *mut i32);
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *std::mem::transmute::<_, *mut i32>(num);
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+
+    let deferred = num as *const i32 as *mut i32;
+    let _num = &mut *deferred;
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).cast_mut() as *mut i32;
+    let _num = &mut *deferred;
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    let _num = &mut *(num as *const _ as usize as *mut i32);
+    //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+
+    unsafe fn generic_ref_cast_mut<T>(this: &T) -> &mut T {
+        &mut *((this as *const _) as *mut _)
+        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    }
+}
+
+unsafe fn assign_to_ref() {
     let s = String::from("Hello");
     let a = &s;
-    unsafe {
-        let num = &3i32;
-        let mut_num = &mut 3i32;
+    let num = &3i32;
 
-        (*(a as *const _ as *mut String)).push_str(" world");
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *(a as *const _ as *mut _) = String::from("Replaced");
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *(a as *const _ as *mut String) += " world";
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        let _num = &mut *(num as *const i32 as *mut i32);
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        let _num = &mut *(num as *const i32).cast_mut();
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        let _num = *{ num as *const i32 }.cast_mut();
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *std::ptr::from_ref(num).cast_mut() += 1;
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *std::ptr::from_ref({ num }).cast_mut() += 1;
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *{ std::ptr::from_ref(num) }.cast_mut() += 1;
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
-        *(std::ptr::from_ref({ num }) as *mut i32) += 1;
-        //~^ ERROR casting `&T` to `&mut T` is undefined behavior
+    *(a as *const _ as *mut _) = String::from("Replaced");
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *(a as *const _ as *mut String) += " world";
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *std::ptr::from_ref(num).cast_mut() += 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *std::ptr::from_ref({ num }).cast_mut() += 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *{ std::ptr::from_ref(num) }.cast_mut() += 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *(std::ptr::from_ref({ num }) as *mut i32) += 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *std::mem::transmute::<_, *mut i32>(num) += 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+
+    let value = num as *const i32 as *mut i32;
+    *value = 1;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *(num as *const i32).cast::<i32>().cast_mut() = 2;
+    //~^ ERROR assigning to `&T` is undefined behavior
+    *(num as *const _ as usize as *mut i32) = 2;
+    //~^ ERROR assigning to `&T` is undefined behavior
 
-        // Shouldn't be warned against
-        println!("{}", *(num as *const _ as *const i16));
-        println!("{}", *(mut_num as *mut _ as *mut i16));
-        ffi(a.as_ptr() as *mut _);
-        int_ffi(num as *const _ as *mut _);
-        int_ffi(&3 as *const _ as *mut _);
-        let mut value = 3;
-        let value: *const i32 = &mut value;
-        *(value as *const i16 as *mut i16) = 42;
+    unsafe fn generic_assign_to_ref<T>(this: &T, a: T) {
+        *(this as *const _ as *mut _) = a;
+        //~^ ERROR assigning to `&T` is undefined behavior
     }
 }
+
+unsafe fn no_warn() {
+    let num = &3i32;
+    let mut_num = &mut 3i32;
+    let a = &String::from("ffi");
+
+    *(num as *const i32 as *mut i32);
+    println!("{}", *(num as *const _ as *const i16));
+    println!("{}", *(mut_num as *mut _ as *mut i16));
+    ffi(a.as_ptr() as *mut _);
+    int_ffi(num as *const _ as *mut _);
+    int_ffi(&3 as *const _ as *mut _);
+    let mut value = 3;
+    let value: *const i32 = &mut value;
+    *(value as *const i16 as *mut i16) = 42;
+}
+
+fn main() {}