Make transmuting from fn item types to pointer-sized types a hard error.

3 files changed, 48 insertions, 77 deletions

diff --git a/src/test/compile-fail/transmute-from-fn-item-types-error.rs b/src/test/compile-fail/transmute-from-fn-item-types-error.rs
index 50bcd53ecb8..c3fe1de895d 100644
--- a/src/test/compile-fail/transmute-from-fn-item-types-error.rs
+++ b/src/test/compile-fail/transmute-from-fn-item-types-error.rs
@@ -10,14 +10,61 @@
 
 use std::mem;
 
+unsafe fn foo() -> (isize, *const (), Option<fn()>) {
+    let i = mem::transmute(bar);
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    let p = mem::transmute(foo);
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    let of = mem::transmute(main);
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    (i, p, of)
+}
+
 unsafe fn bar() {
-    // Error, still, if the resulting type is not pointer-sized.
+    // Error as usual if the resulting type is not pointer-sized.
     mem::transmute::<_, u8>(main);
     //~^ ERROR transmute called with differently sized types
+    //~^^ NOTE transmuting between 0 bits and 8 bits
+
+    mem::transmute::<_, *mut ()>(foo);
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    mem::transmute::<_, fn()>(bar);
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    // No error if a coercion would otherwise occur.
+    mem::transmute::<fn(), usize>(main);
+}
+
+unsafe fn baz() {
+    mem::transmute::<_, *mut ()>(Some(foo));
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    mem::transmute::<_, fn()>(Some(bar));
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    mem::transmute::<_, Option<fn()>>(Some(baz));
+    //~^ ERROR is zero-sized and can't be transmuted
+    //~^^ NOTE cast with `as` to a pointer instead
+
+    // No error if a coercion would otherwise occur.
+    mem::transmute::<Option<fn()>, usize>(Some(main));
 }
 
 fn main() {
     unsafe {
+        foo();
         bar();
+        baz();
     }
 }
diff --git a/src/test/compile-fail/transmute-from-fn-item-types-lint.rs b/src/test/compile-fail/transmute-from-fn-item-types-lint.rs
deleted file mode 100644
index 08e660e878c..00000000000
--- a/src/test/compile-fail/transmute-from-fn-item-types-lint.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#![deny(transmute_from_fn_item_types)]
-
-use std::mem;
-
-unsafe fn foo() -> (isize, *const (), Option<fn()>) {
-    let i = mem::transmute(bar);
-    //~^ ERROR is now zero-sized and has to be cast to a pointer before transmuting
-    //~^^ WARNING was previously accepted
-
-    let p = mem::transmute(foo);
-    //~^ ERROR is now zero-sized and has to be cast to a pointer before transmuting
-    //~^^ WARNING was previously accepted
-
-    let of = mem::transmute(main);
-    //~^ ERROR is now zero-sized and has to be cast to a pointer before transmuting
-    //~^^ WARNING was previously accepted
-
-    (i, p, of)
-}
-
-unsafe fn bar() {
-    mem::transmute::<_, *mut ()>(foo);
-    //~^ ERROR is now zero-sized and has to be cast to a pointer before transmuting
-    //~^^ WARNING was previously accepted
-
-    mem::transmute::<_, fn()>(bar);
-    //~^ ERROR is now zero-sized and has to be cast to a pointer before transmuting
-    //~^^ WARNING was previously accepted
-
-    // No error if a coercion would otherwise occur.
-    mem::transmute::<fn(), usize>(main);
-}
-
-fn main() {
-    unsafe {
-        foo();
-        bar();
-    }
-}
diff --git a/src/test/run-pass/transmute-from-fn-item-types.rs b/src/test/run-pass/transmute-from-fn-item-types.rs
deleted file mode 100644
index 574a90e2ad6..00000000000
--- a/src/test/run-pass/transmute-from-fn-item-types.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#![allow(transmute_from_fn_item_types)]
-
-use std::mem;
-
-fn main() {
-    unsafe {
-        let u = mem::transmute(main);
-        let p = mem::transmute(main);
-        let f = mem::transmute(main);
-        let tuple: (usize, *mut (), fn()) = (u, p, f);
-        assert_eq!(mem::transmute::<_, [usize; 3]>(tuple), [main as usize; 3]);
-
-        mem::transmute::<_, usize>(main);
-        mem::transmute::<_, *mut ()>(main);
-        mem::transmute::<_, fn()>(main);
-    }
-}