From 25babe9a79a2c5d35211e0d6bad348637ef2a246 Mon Sep 17 00:00:00 2001
From: The 8472 <git@infinite-source.de>
Date: Sun, 21 Apr 2024 16:34:42 +0200
Subject: [PATCH] export assert_unsafe_precondition macro for std-internal use

---
 library/core/src/intrinsics.rs | 2 +-
 library/core/src/lib.rs        | 4 +++-
 library/core/src/ub_checks.rs  | 8 ++++++--
 library/std/src/lib.rs         | 1 +
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index 9406efd7ab2..7d2b84b9864 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -2720,7 +2720,7 @@ pub const fn is_val_statically_known<T: Copy>(_arg: T) -> bool {
 #[unstable(feature = "core_intrinsics", issue = "none")]
 #[inline(always)]
 #[cfg_attr(not(bootstrap), rustc_intrinsic)] // just make it a regular fn in bootstrap
-pub(crate) const fn ub_checks() -> bool {
+pub const fn ub_checks() -> bool {
     cfg!(debug_assertions)
 }
 
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 154565b6fee..a7dcc4992f5 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -193,6 +193,7 @@
 #![feature(str_split_inclusive_remainder)]
 #![feature(str_split_remainder)]
 #![feature(strict_provenance)]
+#![feature(ub_checks)]
 #![feature(unchecked_shifts)]
 #![feature(utf16_extra)]
 #![feature(utf16_extra_const)]
@@ -370,7 +371,8 @@ pub mod assert_matches {
 pub mod intrinsics;
 pub mod mem;
 pub mod ptr;
-mod ub_checks;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub mod ub_checks;
 
 /* Core language traits */
 
diff --git a/library/core/src/ub_checks.rs b/library/core/src/ub_checks.rs
index ff6b2d30539..1aa6a288e70 100644
--- a/library/core/src/ub_checks.rs
+++ b/library/core/src/ub_checks.rs
@@ -46,6 +46,8 @@
 /// variables cannot be optimized out in MIR, an innocent-looking `let` can produce enough
 /// debuginfo to have a measurable compile-time impact on debug builds.
 #[allow_internal_unstable(const_ub_checks)] // permit this to be called in stably-const fn
+#[macro_export]
+#[unstable(feature = "ub_checks", issue = "none")]
 macro_rules! assert_unsafe_precondition {
     ($kind:ident, $message:expr, ($($name:ident:$ty:ty = $arg:expr),*$(,)?) => $e:expr $(,)?) => {
         {
@@ -75,11 +77,13 @@ const fn precondition_check($($name:$ty),*) {
         }
     };
 }
-pub(crate) use assert_unsafe_precondition;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub use assert_unsafe_precondition;
 
 /// Checking library UB is always enabled when UB-checking is done
 /// (and we use a reexport so that there is no unnecessary wrapper function).
-pub(crate) use intrinsics::ub_checks as check_library_ub;
+#[unstable(feature = "ub_checks", issue = "none")]
+pub use intrinsics::ub_checks as check_library_ub;
 
 /// Determines whether we should check for language UB.
 ///
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 241a443fab9..3055c638e2c 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -358,6 +358,7 @@
 #![feature(str_internals)]
 #![feature(strict_provenance)]
 #![feature(strict_provenance_atomic_ptr)]
+#![feature(ub_checks)]
 // tidy-alphabetical-end
 //
 // Library features (alloc):