Make TLS keys actually take up space

If the TLS key is 0-sized, then the linux linker is apparently smart enough to
put everything at the same pointer. OSX on the other hand, will reserve some
space for all of them. To get around this, the TLS key now actuall consumes
space to ensure that it gets a unique pointer

1 files changed, 12 insertions, 7 deletions

diff --git a/src/libstd/task/spawn.rs b/src/libstd/task/spawn.rs
index 27cb1c2c100..206d19e175f 100644
--- a/src/libstd/task/spawn.rs
+++ b/src/libstd/task/spawn.rs
@@ -80,6 +80,7 @@ use cell::Cell;
 use container::MutableMap;
 use comm::{Chan, GenericChan};
 use hashmap::HashSet;
+use local_data;
 use task::local_data_priv::{local_get, local_set, OldHandle};
 use task::rt::rust_task;
 use task::rt;
@@ -465,10 +466,14 @@ fn kill_taskgroup(state: TaskGroupInner, me: *rust_task, is_main: bool) {
 
 // FIXME (#2912): Work around core-vs-coretest function duplication. Can't use
 // a proper closure because the #[test]s won't understand. Have to fake it.
-macro_rules! taskgroup_key (
-    // Use a "code pointer" value that will never be a real code pointer.
-    () => (cast::transmute((-2 as uint, 0u)))
-)
+#[cfg(not(stage0))]
+fn taskgroup_key() -> local_data::Key<@@mut TCB> {
+    unsafe { cast::transmute(-2) }
+}
+#[cfg(stage0)]
+fn taskgroup_key() -> local_data::Key<@@mut TCB> {
+    unsafe { cast::transmute((-2, 0)) }
+}
 
 fn gen_child_taskgroup(linked: bool, supervised: bool)
     -> (TaskGroupArc, AncestorList, bool) {
@@ -478,7 +483,7 @@ fn gen_child_taskgroup(linked: bool, supervised: bool)
          * Step 1. Get spawner's taskgroup info.
          *##################################################################*/
         let spawner_group: @@mut TCB =
-            do local_get(OldHandle(spawner), taskgroup_key!()) |group| {
+            do local_get(OldHandle(spawner), taskgroup_key()) |group| {
                 match group {
                     None => {
                         // Main task, doing first spawn ever. Lazily initialise
@@ -495,7 +500,7 @@ fn gen_child_taskgroup(linked: bool, supervised: bool)
                                               AncestorList(None),
                                               true,
                                               None);
-                        local_set(OldHandle(spawner), taskgroup_key!(), group);
+                        local_set(OldHandle(spawner), taskgroup_key(), group);
                         group
                     }
                     Some(&group) => group
@@ -688,7 +693,7 @@ fn spawn_raw_oldsched(mut opts: TaskOpts, f: ~fn()) {
                                       is_main,
                                       notifier);
                 unsafe {
-                    local_set(OldHandle(child), taskgroup_key!(), group);
+                    local_set(OldHandle(child), taskgroup_key(), group);
                 }
 
                 // Run the child's body.