Auto merge of #1778 - RalfJung:thread-local-const-init, r=RalfJung

test thread_local_const_init

Blocked on rust-lang/rust#84291

rust-version

@@ -1 +1 @@
-3833636446b670ee905fba5f8d18881b1739814e
+b2c20b51ed838368d3f2bdccb63f401bcddb7e1c

tests/run-pass/concurrency/tls_lib_drop.rs

@@ -1,4 +1,5 @@
 // ignore-windows: Concurrency on Windows is not supported yet.
+#![feature(thread_local_const_init)]
 
 use std::cell::RefCell;
 use std::thread;
@@ -16,6 +17,7 @@ impl Drop for TestCell {
 
 thread_local! {
     static A: TestCell = TestCell { value: RefCell::new(0) };
+    static A_CONST: TestCell = const { TestCell { value: RefCell::new(10) } };
 }
 
 /// Check that destructors of the library thread locals are executed immediately
@@ -26,6 +28,10 @@ fn check_destructors() {
             assert_eq!(*f.value.borrow(), 0);
             *f.value.borrow_mut() = 5;
         });
+        A_CONST.with(|f| {
+            assert_eq!(*f.value.borrow(), 10);
+            *f.value.borrow_mut() = 15;
+        });
     })
     .join()
     .unwrap();

tests/run-pass/concurrency/tls_lib_drop.stdout

@@ -1,4 +1,5 @@
 Dropping: 5 (should be before 'Continue main 1').
+Dropping: 15 (should be before 'Continue main 1').
 Continue main 1.
 Joining: 7 (should be before 'Continue main 2').
 Continue main 2.

tests/run-pass/concurrency/tls_lib_drop_single_thread.rs

@@ -1,4 +1,6 @@
+// compile-flags: -Zmiri-track-raw-pointers
 //! Check that destructors of the thread locals are executed on all OSes.
+#![feature(thread_local_const_init)]
 
 use std::cell::RefCell;
 
@@ -14,12 +16,17 @@ impl Drop for TestCell {
 
 thread_local! {
     static A: TestCell = TestCell { value: RefCell::new(0) };
+    static A_CONST: TestCell = const { TestCell { value: RefCell::new(10) } };
 }
 
 fn main() {
     A.with(|f| {
         assert_eq!(*f.value.borrow(), 0);
         *f.value.borrow_mut() = 5;
     });
+    A_CONST.with(|f| {
+        assert_eq!(*f.value.borrow(), 10);
+        *f.value.borrow_mut() = 5; // Same value as above since the drop order is different on different platforms
+    });
     eprintln!("Continue main.")
 }

tests/run-pass/concurrency/tls_lib_drop_single_thread.stderr

@@ -1,2 +1,3 @@
 Continue main.
 Dropping: 5
+Dropping: 5