Unrolled build for #123356

Rollup merge of #123356 - joboet:set_current_size, r=ChrisDenton

Reduce code size of `thread::set_current`

#123265 introduced a rather large binary size regression, because it added an `unwrap()` call on a `Result<(), Thread>`, which in turn pulled its rather heavy `Debug` implementation. This PR fixes this by readding the `rtassert!` that was removed.

library/std/src/thread/mod.rs

@@ -703,9 +703,14 @@ thread_local! {
 
 /// Sets the thread handle for the current thread.
 ///
-/// Panics if the handle has been set already or when called from a TLS destructor.
+/// Aborts if the handle has been set already to reduce code size.
 pub(crate) fn set_current(thread: Thread) {
- CURRENT.with(|current| current.set(thread).unwrap());
+ // Using `unwrap` here can add ~3kB to the binary size. We have complete
+ // control over where this is called, so just abort if there is a bug.
+ CURRENT.with(|current| match current.set(thread) {
+ Ok(()) => {}
+ Err(_) => rtabort!("thread::set_current should only be called once per thread"),
+ });
 }
 
 /// Gets a handle to the thread that invokes it.