diff -r 000000000000 -r 6474c204b198 build/clang-plugin/tests/TestCustomHeap.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/clang-plugin/tests/TestCustomHeap.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+#define MOZ_NONHEAP_CLASS __attribute__((annotate("moz_nonheap_class")))
+#define MOZ_HEAP_ALLOCATOR \
+  _Pragma("GCC diagnostic push") \
+  _Pragma("GCC diagnostic ignored \"-Wgcc-compat\"") \
+  __attribute__((annotate("moz_heap_allocator"))) \
+  _Pragma("GCC diagnostic pop")
+
+#include <stdlib.h>
+#include <memory>
+
+struct MOZ_NONHEAP_CLASS X {
+};
+
+void *operator new(size_t x, int qual) MOZ_HEAP_ALLOCATOR {
+  return ::operator new(x);
+}
+
+template <typename T>
+T *customAlloc() MOZ_HEAP_ALLOCATOR {
+  T *arg =  static_cast<T*>(malloc(sizeof(T)));
+  return new (arg) T();
+}
+
+template <typename T>
+void misuseX(T q) {
+  X *foo = customAlloc<X>(); // expected-error {{variable of type 'X' is not valid on the heap}}
+  X *foo2 = new (100) X(); // expected-error {{variable of type 'X' is not valid on the heap}}
+}