Support foreign 'static mut' variables as well

src/test/compile-fail/static-mut-foreign-requires-unsafe.rs

@@ -0,0 +1,21 @@
+// Copyright 2013 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.
+
+use std::libc;
+
+extern {
+    static mut a: libc::c_int;
+}
+
+fn main() {
+    a += 3;     //~ ERROR: requires unsafe
+    a = 4;      //~ ERROR: requires unsafe
+    let _b = a; //~ ERROR: requires unsafe
+}

src/test/run-pass/static-mut-foreign.rs

@@ -0,0 +1,46 @@
+// Copyright 2013 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.
+
+// Constants (static variables) can be used to match in patterns, but mutable
+// statics cannot. This ensures that there's some form of error if this is
+// attempted.
+
+use std::libc;
+
+#[nolink]
+extern {
+    static mut debug_static_mut: libc::c_int;
+    pub fn debug_static_mut_check_four();
+}
+
+unsafe fn static_bound(_: &'static libc::c_int) {}
+
+fn static_bound_set(a: &'static mut libc::c_int) {
+    *a = 3;
+}
+
+unsafe fn run() {
+    assert!(debug_static_mut == 3);
+    debug_static_mut = 4;
+    assert!(debug_static_mut == 4);
+    debug_static_mut_check_four();
+    debug_static_mut += 1;
+    assert!(debug_static_mut == 5);
+    debug_static_mut *= 3;
+    assert!(debug_static_mut == 15);
+    debug_static_mut = -3;
+    assert!(debug_static_mut == -3);
+    static_bound(&debug_static_mut);
+    static_bound_set(&mut debug_static_mut);
+}
+
+fn main() {
+    unsafe { run() }
+}