Rollup merge of #106879 - JohnTitor:issue-42114, r=compiler-errors

[rust.git] / library / alloc / src / lib.rs

diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 9857f0516baa217f84fc0e66223c4e53bf0da7a4..4e812529c2cc846d7934672a05202a0eb9db7218 100644 (file)
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -110,6 +110,7 @@
 #![feature(const_maybe_uninit_as_mut_ptr)]
 #![feature(const_refs_to_cell)]
 #![feature(core_intrinsics)]
+#![feature(core_panic)]
 #![feature(const_eval_select)]
 #![feature(const_pin)]
 #![feature(const_waker)]
@@ -191,6 +192,7 @@
 #![feature(unsized_fn_params)]
 #![feature(c_unwind)]
 #![feature(with_negative_coherence)]
+#![cfg_attr(test, feature(panic_update_hook))]
 //
 // Rustdoc features:
 #![feature(doc_cfg)]
@@ -254,3 +256,20 @@ mod boxed {
 pub mod __export {
     pub use core::format_args;
 }
+
+#[cfg(test)]
+#[allow(dead_code)] // Not used in all configurations
+pub(crate) mod test_helpers {
+    /// Copied from `std::test_helpers::test_rng`, since these tests rely on the
+    /// seed not being the same for every RNG invocation too.
+    pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
+        use std::hash::{BuildHasher, Hash, Hasher};
+        let mut hasher = std::collections::hash_map::RandomState::new().build_hasher();
+        std::panic::Location::caller().hash(&mut hasher);
+        let hc64 = hasher.finish();
+        let seed_vec =
+            hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<crate::vec::Vec<u8>>();
+        let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
+        rand::SeedableRng::from_seed(seed)
+    }
+}