1 files changed, 46 insertions, 0 deletions
diff --git a/src/libstd/sys/wasm/thread.rs b/src/libstd/sys/wasm/thread.rs
index bef6c1f3490..4ad89c42b92 100644
--- a/src/libstd/sys/wasm/thread.rs
+++ b/src/libstd/sys/wasm/thread.rs
@@ -69,3 +69,49 @@ pub mod guard {
     pub unsafe fn init() -> Option<Guard> { None }
     pub unsafe fn deinit() {}
 }
+
+cfg_if! {
+    if #[cfg(all(target_feature = "atomics", feature = "wasm-bindgen-threads"))] {
+        #[link(wasm_import_module = "__wbindgen_thread_xform__")]
+        extern {
+            fn __wbindgen_current_id() -> u32;
+            fn __wbindgen_tcb_get() -> u32;
+            fn __wbindgen_tcb_set(ptr: u32);
+        }
+        pub fn my_id() -> u32 {
+            unsafe { __wbindgen_current_id() }
+        }
+
+        // These are currently only ever used in `thread_local_atomics.rs`, if
+        // you'd like to use them be sure to update that and make sure everyone
+        // agrees what's what.
+        pub fn tcb_get() -> *mut u8 {
+            use mem;
+            assert_eq!(mem::size_of::<*mut u8>(), mem::size_of::<u32>());
+            unsafe { __wbindgen_tcb_get() as *mut u8 }
+        }
+
+        pub fn tcb_set(ptr: *mut u8) {
+            unsafe { __wbindgen_tcb_set(ptr as u32); }
+        }
+
+        // FIXME: still need something for hooking exiting a thread to free
+        // data...
+
+    } else if #[cfg(target_feature = "atomics")] {
+        pub fn my_id() -> u32 {
+            panic!("thread ids not implemented on wasm with atomics yet")
+        }
+
+        pub fn tcb_get() -> *mut u8 {
+            panic!("thread local data not implemented on wasm with atomics yet")
+        }
+
+        pub fn tcb_set(ptr: *mut u8) {
+            panic!("thread local data not implemented on wasm with atomics yet")
+        }
+    } else {
+        // stubbed out because no functions actually access these intrinsics
+        // unless atomics are enabled
+    }
+}