Auto merge of #92587 - matthiaskrgr:rollup-qnwa8qx, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #92092 (Drop guards in slice sorting derive src pointers from &mut T, which is invalidated by interior mutation in comparison)
 - #92388 (Fix a minor mistake in `String::try_reserve_exact` examples)
 - #92442 (Add negative `impl` for `Ord`, `PartialOrd` on `LocalDefId`)
 - #92483 (Stabilize `result_cloned` and `result_copied`)
 - #92574 (Add RISC-V detection macro and more architecture instructions)
 - #92575 (ast: Always keep a `NodeId` in `ast::Crate`)
 - #92583 (:arrow_up: rust-analyzer)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

alloc/src/slice.rs

@@ -892,7 +892,7 @@ where
             //    performance than with the 2nd method.
             //
             // All methods were benchmarked, and the 3rd showed best results. So we chose that one.
-            let mut tmp = mem::ManuallyDrop::new(ptr::read(&v[0]));
+            let tmp = mem::ManuallyDrop::new(ptr::read(&v[0]));
 
             // Intermediate state of the insertion process is always tracked by `hole`, which
             // serves two purposes:
@@ -904,7 +904,7 @@ where
             // If `is_less` panics at any point during the process, `hole` will get dropped and
             // fill the hole in `v` with `tmp`, thus ensuring that `v` still holds every object it
             // initially held exactly once.
-            let mut hole = InsertionHole { src: &mut *tmp, dest: &mut v[1] };
+            let mut hole = InsertionHole { src: &*tmp, dest: &mut v[1] };
             ptr::copy_nonoverlapping(&v[1], &mut v[0], 1);
 
             for i in 2..v.len() {
@@ -920,7 +920,7 @@ where
 
     // When dropped, copies from `src` into `dest`.
     struct InsertionHole<T> {
-        src: *mut T,
+        src: *const T,
         dest: *mut T,
     }
 

alloc/src/string.rs

@@ -1062,7 +1062,7 @@ impl String {
     ///     let mut output = String::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
-    ///     output.try_reserve(data.len())?;
+    ///     output.try_reserve_exact(data.len())?;
     ///
     ///     // Now we know this can't OOM in the middle of our complex work
     ///     output.push_str(data);

core/src/hint.rs

@@ -123,6 +123,21 @@ pub fn spin_loop() {
         }
     }
 
+    // RISC-V platform spin loop hint implementation
+    {
+        // RISC-V RV32 and RV64 share the same PAUSE instruction, but they are located in different
+        // modules in `core::arch`.
+        // In this case, here we call `pause` function in each core arch module.
+        #[cfg(target_arch = "riscv32")]
+        {
+            crate::arch::riscv32::pause();
+        }
+        #[cfg(target_arch = "riscv64")]
+        {
+            crate::arch::riscv64::pause();
+        }
+    }
+
     #[cfg(any(target_arch = "aarch64", all(target_arch = "arm", target_feature = "v6")))]
     {
         #[cfg(target_arch = "aarch64")]
@@ -137,11 +152,6 @@ pub fn spin_loop() {
             unsafe { crate::arch::arm::__yield() };
         }
     }
-
-    #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
-    {
-        crate::arch::riscv::pause();
-    }
 }
 
 /// An identity function that *__hints__* to the compiler to be maximally pessimistic about what

core/src/result.rs

@@ -1504,14 +1504,14 @@ impl<T, E> Result<&T, E> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(result_copied)]
     /// let val = 12;
     /// let x: Result<&i32, i32> = Ok(&val);
     /// assert_eq!(x, Ok(&12));
     /// let copied = x.copied();
     /// assert_eq!(copied, Ok(12));
     /// ```
-    #[unstable(feature = "result_copied", reason = "newly added", issue = "63168")]
+    #[inline]
+    #[stable(feature = "result_copied", since = "1.59.0")]
     pub fn copied(self) -> Result<T, E>
     where
         T: Copy,
@@ -1525,14 +1525,14 @@ impl<T, E> Result<&T, E> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(result_cloned)]
     /// let val = 12;
     /// let x: Result<&i32, i32> = Ok(&val);
     /// assert_eq!(x, Ok(&12));
     /// let cloned = x.cloned();
     /// assert_eq!(cloned, Ok(12));
     /// ```
-    #[unstable(feature = "result_cloned", reason = "newly added", issue = "63168")]
+    #[inline]
+    #[stable(feature = "result_cloned", since = "1.59.0")]
     pub fn cloned(self) -> Result<T, E>
     where
         T: Clone,
@@ -1548,14 +1548,14 @@ impl<T, E> Result<&mut T, E> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(result_copied)]
     /// let mut val = 12;
     /// let x: Result<&mut i32, i32> = Ok(&mut val);
     /// assert_eq!(x, Ok(&mut 12));
     /// let copied = x.copied();
     /// assert_eq!(copied, Ok(12));
     /// ```
-    #[unstable(feature = "result_copied", reason = "newly added", issue = "63168")]
+    #[inline]
+    #[stable(feature = "result_copied", since = "1.59.0")]
     pub fn copied(self) -> Result<T, E>
     where
         T: Copy,
@@ -1569,14 +1569,14 @@ impl<T, E> Result<&mut T, E> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(result_cloned)]
     /// let mut val = 12;
     /// let x: Result<&mut i32, i32> = Ok(&mut val);
     /// assert_eq!(x, Ok(&mut 12));
     /// let cloned = x.cloned();
     /// assert_eq!(cloned, Ok(12));
     /// ```
-    #[unstable(feature = "result_cloned", reason = "newly added", issue = "63168")]
+    #[inline]
+    #[stable(feature = "result_cloned", since = "1.59.0")]
     pub fn cloned(self) -> Result<T, E>
     where
         T: Clone,

core/src/slice/sort.rs

@@ -12,7 +12,7 @@ use crate::ptr;
 
 /// When dropped, copies from `src` into `dest`.
 struct CopyOnDrop<T> {
-    src: *mut T,
+    src: *const T,
     dest: *mut T,
 }
 
@@ -54,9 +54,9 @@ where
             // Read the first element into a stack-allocated variable. If a following comparison
             // operation panics, `hole` will get dropped and automatically write the element back
             // into the slice.
-            let mut tmp = mem::ManuallyDrop::new(ptr::read(v.get_unchecked(0)));
+            let tmp = mem::ManuallyDrop::new(ptr::read(v.get_unchecked(0)));
             let v = v.as_mut_ptr();
-            let mut hole = CopyOnDrop { src: &mut *tmp, dest: v.add(1) };
+            let mut hole = CopyOnDrop { src: &*tmp, dest: v.add(1) };
             ptr::copy_nonoverlapping(v.add(1), v.add(0), 1);
 
             for i in 2..len {
@@ -100,9 +100,9 @@ where
             // Read the last element into a stack-allocated variable. If a following comparison
             // operation panics, `hole` will get dropped and automatically write the element back
             // into the slice.
-            let mut tmp = mem::ManuallyDrop::new(ptr::read(v.get_unchecked(len - 1)));
+            let tmp = mem::ManuallyDrop::new(ptr::read(v.get_unchecked(len - 1)));
             let v = v.as_mut_ptr();
-            let mut hole = CopyOnDrop { src: &mut *tmp, dest: v.add(len - 2) };
+            let mut hole = CopyOnDrop { src: &*tmp, dest: v.add(len - 2) };
             ptr::copy_nonoverlapping(v.add(len - 2), v.add(len - 1), 1);
 
             for i in (0..len - 2).rev() {
@@ -498,8 +498,8 @@ where
         // operation panics, the pivot will be automatically written back into the slice.
 
         // SAFETY: `pivot` is a reference to the first element of `v`, so `ptr::read` is safe.
-        let mut tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
-        let _pivot_guard = CopyOnDrop { src: &mut *tmp, dest: pivot };
+        let tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
+        let _pivot_guard = CopyOnDrop { src: &*tmp, dest: pivot };
         let pivot = &*tmp;
 
         // Find the first pair of out-of-order elements.
@@ -551,8 +551,8 @@ where
     // Read the pivot into a stack-allocated variable for efficiency. If a following comparison
     // operation panics, the pivot will be automatically written back into the slice.
     // SAFETY: The pointer here is valid because it is obtained from a reference to a slice.
-    let mut tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
-    let _pivot_guard = CopyOnDrop { src: &mut *tmp, dest: pivot };
+    let tmp = mem::ManuallyDrop::new(unsafe { ptr::read(pivot) });
+    let _pivot_guard = CopyOnDrop { src: &*tmp, dest: pivot };
     let pivot = &*tmp;
 
     // Now partition the slice.

std/src/lib.rs

@@ -556,6 +556,7 @@ pub use std_detect::*;
 pub use std_detect::{
     is_aarch64_feature_detected, is_arm_feature_detected, is_mips64_feature_detected,
     is_mips_feature_detected, is_powerpc64_feature_detected, is_powerpc_feature_detected,
+    is_riscv_feature_detected,
 };
 
 // Re-export macros defined in libcore.

stdarch

@@ -1 +1 @@
-Subproject commit 0716b22e902207efabe46879cbf28d0189ab7924
+Subproject commit 2adc17a5442614dbe34626fdd9b32de7c07b8086