Rollup merge of #106397 - compiler-errors:new-solver-impl-wc, r=lcnr

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

diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 13dfd41abbf84ddd42b8d17dd138dd2beb3c367d..a7e13f5b866b53058f0f995f5818e739c47c09de 100644 (file)
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -14,7 +14,7 @@
 //! # How to read this documentation
 //!
 //! If you already know the name of what you are looking for, the fastest way to
-//! find it is to use the <a href="#" onclick="focusSearchBar();">search
+//! find it is to use the <a href="#" onclick="window.searchState.focus();">search
 //! bar</a> at the top of the page.
 //!
 //! Otherwise, you may want to jump to one of these useful sections:
@@ -652,3 +652,30 @@ mod sealed {
     #[unstable(feature = "sealed", issue = "none")]
     pub trait Sealed {}
 }
+
+#[cfg(test)]
+#[allow(dead_code)] // Not used in all configurations.
+pub(crate) mod test_helpers {
+    /// Test-only replacement for `rand::thread_rng()`, which is unusable for
+    /// us, as we want to allow running stdlib tests on tier-3 targets which may
+    /// not have `getrandom` support.
+    ///
+    /// Does a bit of a song and dance to ensure that the seed is different on
+    /// each call (as some tests sadly rely on this), but doesn't try that hard.
+    ///
+    /// This is duplicated in the `core`, `alloc` test suites (as well as
+    /// `std`'s integration tests), but figuring out a mechanism to share these
+    /// seems far more painful than copy-pasting a 7 line function a couple
+    /// times, given that even under a perma-unstable feature, I don't think we
+    /// want to expose types from `rand` from `std`.
+    #[track_caller]
+    pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
+        use core::hash::{BuildHasher, Hash, Hasher};
+        let mut hasher = crate::collections::hash_map::RandomState::new().build_hasher();
+        core::panic::Location::caller().hash(&mut hasher);
+        let hc64 = hasher.finish();
+        let seed_vec = hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<Vec<u8>>();
+        let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
+        rand::SeedableRng::from_seed(seed)
+    }
+}