copy over *.fixed file

Author: Ryan1729

src/tools/clippy/tests/ui/transmutes_expressible_as_ptr_casts.fixed

@@ -0,0 +1,77 @@
+// run-rustfix
+#![warn(clippy::transmutes_expressible_as_ptr_casts)]
+// These two warnings currrently cover the cases transmutes_expressible_as_ptr_casts
+// would otherwise be responsible for
+#![warn(clippy::useless_transmute)]
+#![warn(clippy::transmute_ptr_to_ptr)]
+
+use std::mem::transmute;
+
+// rustc_typeck::check::cast contains documentation about when a cast `e as U` is 
+// valid, which we quote from below.
+
+fn main() {
+    // We should see an error message for each transmute, and no error messages for
+    // the casts, since the casts are the recommended fixes.
+
+    // e is an integer and U is *U_0, while U_0: Sized; addr-ptr-cast
+    let ptr_i32_transmute = unsafe {
+        -1 as *const i32
+    };
+    let ptr_i32 = -1isize as *const i32;
+
+    // e has type *T, U is *U_0, and either U_0: Sized ...
+    let ptr_i8_transmute = unsafe {
+        ptr_i32 as *const i8
+    };
+    let ptr_i8 = ptr_i32 as *const i8;
+
+    let slice_ptr = &[0,1,2,3] as *const [i32];
+
+    // ... or pointer_kind(T) = pointer_kind(U_0); ptr-ptr-cast
+    let ptr_to_unsized_transmute = unsafe {
+        slice_ptr as *const [u16]
+    };
+    let ptr_to_unsized = slice_ptr as *const [u16];
+    // TODO: We could try testing vtable casts here too, but maybe
+    // we should wait until std::raw::TraitObject is stabilized?
+
+    // e has type *T and U is a numeric type, while T: Sized; ptr-addr-cast
+    let usize_from_int_ptr_transmute = unsafe {
+        ptr_i32 as usize
+    };
+    let usize_from_int_ptr = ptr_i32 as usize;
+
+    let array_ref: &[i32; 4] = &[1,2,3,4];
+
+    // e has type &[T; n] and U is *const T; array-ptr-cast
+    let array_ptr_transmute = unsafe {
+        array_ref as *const [i32; 4]
+    };
+    let array_ptr = array_ref as *const [i32; 4];
+
+    fn foo(_: usize) -> u8 { 42 }
+
+    // e is a function pointer type and U has type *T, while T: Sized; fptr-ptr-cast
+    let usize_ptr_transmute = unsafe {
+        foo as *const usize
+    };
+    let usize_ptr_transmute = foo as *const usize;
+
+    // e is a function pointer type and U is an integer; fptr-addr-cast
+    let usize_from_fn_ptr_transmute = unsafe {
+        foo as usize
+    };
+    let usize_from_fn_ptr = foo as *const usize;
+}
+
+// If a ref-to-ptr cast of this form where the pointer type points to a type other
+// than the referenced type, calling `CastCheck::do_check` has been observed to
+// cause an ICE error message. `do_check` is currently called inside the
+// `transmutes_expressible_as_ptr_casts` check, but other, more specific lints
+// currently prevent it from being called in these cases. This test is meant to
+// fail if the ordering of the checks ever changes enough to cause these cases to
+// fall through into `do_check`.
+fn trigger_do_check_to_emit_error(in_param: &[i32; 1]) -> *const u8 {
+    unsafe { in_param as *const [i32; 1] as *const u8 }
+}