1 files changed, 61 insertions, 0 deletions
diff --git a/servo/components/hashglobe/src/shim.rs b/servo/components/hashglobe/src/shim.rs
new file mode 100644
index 0000000000..855dbdcfa1
--- /dev/null
+++ b/servo/components/hashglobe/src/shim.rs
@@ -0,0 +1,61 @@
+use std::marker::PhantomData;
+
+// FIXME: remove this and use std::ptr::NonNull when Firefox requires Rust 1.25+
+pub struct NonZeroPtr<T: 'static>(&'static T);
+
+impl<T: 'static> NonZeroPtr<T> {
+    pub unsafe fn new_unchecked(ptr: *mut T) -> Self {
+        NonZeroPtr(&*ptr)
+    }
+    pub fn as_ptr(&self) -> *mut T {
+        self.0 as *const T as *mut T
+    }
+}
+
+pub struct Unique<T: 'static> {
+    ptr: NonZeroPtr<T>,
+    _marker: PhantomData<T>,
+}
+
+impl<T: 'static> Unique<T> {
+    pub unsafe fn new_unchecked(ptr: *mut T) -> Self {
+        Unique {
+            ptr: NonZeroPtr::new_unchecked(ptr),
+            _marker: PhantomData,
+        }
+    }
+    pub fn as_ptr(&self) -> *mut T {
+        self.ptr.as_ptr()
+    }
+}
+
+unsafe impl<T: Send + 'static> Send for Unique<T> {}
+
+unsafe impl<T: Sync + 'static> Sync for Unique<T> {}
+
+pub struct Shared<T: 'static> {
+    ptr: NonZeroPtr<T>,
+    _marker: PhantomData<T>,
+    // force it to be !Send/!Sync
+    _marker2: PhantomData<*const u8>,
+}
+
+impl<T: 'static> Shared<T> {
+    pub unsafe fn new_unchecked(ptr: *mut T) -> Self {
+        Shared {
+            ptr: NonZeroPtr::new_unchecked(ptr),
+            _marker: PhantomData,
+            _marker2: PhantomData,
+        }
+    }
+
+    pub unsafe fn as_mut(&self) -> &mut T {
+        &mut *self.ptr.as_ptr()
+    }
+}
+
+impl<'a, T> From<&'a mut T> for Shared<T> {
+    fn from(reference: &'a mut T) -> Self {
+        unsafe { Shared::new_unchecked(reference) }
+    }
+}