auto merge of #14310 : pcwalton/rust/detildestr-alllibs, r=brson

r? @brson

2 files changed, 23 insertions, 6 deletions

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index 631b72cb897..8376fc578db 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -116,18 +116,18 @@ pub fn stats_print() {
     }
 }
 
+// The compiler never calls `exchange_free` on ~ZeroSizeType, so zero-size
+// allocations can point to this `static`. It would be incorrect to use a null
+// pointer, due to enums assuming types like unique pointers are never null.
+pub static mut EMPTY: uint = 12345;
+
 /// The allocator for unique pointers.
 #[cfg(not(test))]
 #[lang="exchange_malloc"]
 #[inline]
 unsafe fn exchange_malloc(size: uint, align: uint) -> *mut u8 {
-    // The compiler never calls `exchange_free` on ~ZeroSizeType, so zero-size
-    // allocations can point to this `static`. It would be incorrect to use a null
-    // pointer, due to enums assuming types like unique pointers are never null.
-    static EMPTY: () = ();
-
     if size == 0 {
-        &EMPTY as *() as *mut u8
+        &EMPTY as *uint as *mut u8
     } else {
         allocate(size, align)
     }
diff --git a/src/liballoc/util.rs b/src/liballoc/util.rs
index 7e35af79eab..64d62035890 100644
--- a/src/liballoc/util.rs
+++ b/src/liballoc/util.rs
@@ -28,3 +28,20 @@ fn align_to(size: uint, align: uint) -> uint {
     assert!(align != 0);
     (size + align - 1) & !(align - 1)
 }
+
+// FIXME(#14344): When linking liballoc with libstd, this library will be linked
+//                as an rlib (it only exists as an rlib). It turns out that an
+//                optimized standard library doesn't actually use *any* symbols
+//                from this library. Everything is inlined and optimized away.
+//                This means that linkers will actually omit the object for this
+//                file, even though it may be needed in the future.
+//
+//                To get around this for now, we define a dummy symbol which
+//                will never get inlined so the stdlib can call it. The stdlib's
+//                reference to this symbol will cause this library's object file
+//                to get linked in to libstd successfully (the linker won't
+//                optimize it out).
+#[deprecated]
+#[doc(hidden)]
+pub fn make_stdlib_link_work() {}
+