Rollup merge of #106225 - ehuss:ehuss-patch-1, r=GuillaumeGomez

[rust.git] / library / core / src / intrinsics.rs

diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index a521905a9e735b37296ef50bd906a30fe5eb7779..a315a28fb0d943f24deb882e1cdf8937637c5315 100644 (file)
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -55,7 +55,6 @@
 #![allow(missing_docs)]
 
 use crate::marker::DiscriminantKind;
-#[cfg(not(bootstrap))]
 use crate::marker::Tuple;
 use crate::mem;
 
@@ -2175,66 +2174,6 @@ pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
     /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*,
     /// which violates the principle that a `const fn` must behave the same at
     /// compile-time and at run-time. The unsafe code in crate B is fine.
-    #[cfg(bootstrap)]
-    #[rustc_const_unstable(feature = "const_eval_select", issue = "none")]
-    pub fn const_eval_select<ARG, F, G, RET>(arg: ARG, called_in_const: F, called_at_rt: G) -> RET
-    where
-        G: FnOnce<ARG, Output = RET>,
-        F: FnOnce<ARG, Output = RET>;
-
-    /// Selects which function to call depending on the context.
-    ///
-    /// If this function is evaluated at compile-time, then a call to this
-    /// intrinsic will be replaced with a call to `called_in_const`. It gets
-    /// replaced with a call to `called_at_rt` otherwise.
-    ///
-    /// # Type Requirements
-    ///
-    /// The two functions must be both function items. They cannot be function
-    /// pointers or closures. The first function must be a `const fn`.
-    ///
-    /// `arg` will be the tupled arguments that will be passed to either one of
-    /// the two functions, therefore, both functions must accept the same type of
-    /// arguments. Both functions must return RET.
-    ///
-    /// # Safety
-    ///
-    /// The two functions must behave observably equivalent. Safe code in other
-    /// crates may assume that calling a `const fn` at compile-time and at run-time
-    /// produces the same result. A function that produces a different result when
-    /// evaluated at run-time, or has any other observable side-effects, is
-    /// *unsound*.
-    ///
-    /// Here is an example of how this could cause a problem:
-    /// ```no_run
-    /// #![feature(const_eval_select)]
-    /// #![feature(core_intrinsics)]
-    /// use std::hint::unreachable_unchecked;
-    /// use std::intrinsics::const_eval_select;
-    ///
-    /// // Crate A
-    /// pub const fn inconsistent() -> i32 {
-    ///     fn runtime() -> i32 { 1 }
-    ///     const fn compiletime() -> i32 { 2 }
-    ///
-    ///     unsafe {
-    //          // ⚠ This code violates the required equivalence of `compiletime`
-    ///         // and `runtime`.
-    ///         const_eval_select((), compiletime, runtime)
-    ///     }
-    /// }
-    ///
-    /// // Crate B
-    /// const X: i32 = inconsistent();
-    /// let x = inconsistent();
-    /// if x != X { unsafe { unreachable_unchecked(); }}
-    /// ```
-    ///
-    /// This code causes Undefined Behavior when being run, since the
-    /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*,
-    /// which violates the principle that a `const fn` must behave the same at
-    /// compile-time and at run-time. The unsafe code in crate B is fine.
-    #[cfg(not(bootstrap))]
     #[rustc_const_unstable(feature = "const_eval_select", issue = "none")]
     pub fn const_eval_select<ARG: Tuple, F, G, RET>(
         arg: ARG,
@@ -2281,7 +2220,7 @@ macro_rules! assert_unsafe_precondition {
             fn runtime$(<$($tt)*>)?($($i:$ty),*) {
                 if !$e {
                     // don't unwind to reduce impact on code size
-                    ::core::panicking::panic_str_nounwind(
+                    ::core::panicking::panic_nounwind(
                         concat!("unsafe precondition(s) violated: ", $name)
                     );
                 }