Auto merge of rust-lang#122331 - jhpratt:rollup-cbl8xsy, r=jhpratt

Rollup of 9 pull requests

Successful merges:

 - rust-lang#121148 (Add slice::try_range)
 - rust-lang#121633 (Win10: Use `GetSystemTimePreciseAsFileTime` directly)
 - rust-lang#121840 (Expose the Freeze trait again (unstably) and forbid implementing it manually)
 - rust-lang#121907 (skip sanity check for non-host targets in `check` builds)
 - rust-lang#122002 (std::threads: revisit stack address calculation on netbsd.)
 - rust-lang#122108 (Add `target.*.runner` configuration for targets)
 - rust-lang#122298 (RawVec::into_box: avoid unnecessary intermediate reference)
 - rust-lang#122315 (Allow multiple `impl Into<{D,Subd}iagMessage>` parameters in a function.)
 - rust-lang#122326 (Optimize `process_heap_alloc`)

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

Author: bors

alloc/src/raw_vec.rs

@@ -5,7 +5,6 @@ use core::cmp;
 use core::hint;
 use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
 use core::ptr::{self, NonNull, Unique};
-use core::slice;
 
 #[cfg(not(no_global_oom_handling))]
 use crate::alloc::handle_alloc_error;
@@ -192,7 +191,7 @@ impl<T, A: Allocator> RawVec<T, A> {
 
         let me = ManuallyDrop::new(self);
         unsafe {
-            let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
+            let slice = ptr::slice_from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
             Box::from_raw_in(slice, ptr::read(&me.alloc))
         }
     }

alloc/src/slice.rs

@@ -33,8 +33,6 @@ use crate::vec::Vec;
 #[cfg(test)]
 mod tests;
 
-#[unstable(feature = "slice_range", issue = "76393")]
-pub use core::slice::range;
 #[unstable(feature = "array_chunks", issue = "74985")]
 pub use core::slice::ArrayChunks;
 #[unstable(feature = "array_chunks", issue = "74985")]
@@ -51,6 +49,8 @@ pub use core::slice::{from_mut, from_ref};
 pub use core::slice::{from_mut_ptr_range, from_ptr_range};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::slice::{from_raw_parts, from_raw_parts_mut};
+#[unstable(feature = "slice_range", issue = "76393")]
+pub use core::slice::{range, try_range};
 #[stable(feature = "slice_group_by", since = "1.77.0")]
 pub use core::slice::{ChunkBy, ChunkByMut};
 #[stable(feature = "rust1", since = "1.0.0")]

core/src/lib.rs

@@ -204,6 +204,7 @@
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(diagnostic_namespace))]
 #![cfg_attr(bootstrap, feature(platform_intrinsics))]
+#![cfg_attr(not(bootstrap), feature(freeze_impls))]
 #![feature(abi_unadjusted)]
 #![feature(adt_const_params)]
 #![feature(allow_internal_unsafe)]

core/src/marker.rs

@@ -810,15 +810,21 @@ pub trait DiscriminantKind {
     type Discriminant: Clone + Copy + Debug + Eq + PartialEq + Hash + Send + Sync + Unpin;
 }
 
-/// Compiler-internal trait used to determine whether a type contains
+/// Used to determine whether a type contains
 /// any `UnsafeCell` internally, but not through an indirection.
 /// This affects, for example, whether a `static` of that type is
 /// placed in read-only static memory or writable static memory.
+/// This can be used to declare that a constant with a generic type
+/// will not contain interior mutability, and subsequently allow
+/// placing the constant behind references.
 #[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+#[unstable(feature = "freeze", issue = "121675")]
+pub unsafe auto trait Freeze {}
 
+#[unstable(feature = "freeze", issue = "121675")]
 impl<T: ?Sized> !Freeze for UnsafeCell<T> {}
 marker_impls! {
+    #[unstable(feature = "freeze", issue = "121675")]
     unsafe Freeze for
         {T: ?Sized} PhantomData<T>,
         {T: ?Sized} *const T,

core/src/slice/index.rs

@@ -704,17 +704,15 @@ where
 {
     let len = bounds.end;
 
-    let start: ops::Bound<&usize> = range.start_bound();
-    let start = match start {
+    let start = match range.start_bound() {
         ops::Bound::Included(&start) => start,
         ops::Bound::Excluded(start) => {
             start.checked_add(1).unwrap_or_else(|| slice_start_index_overflow_fail())
         }
         ops::Bound::Unbounded => 0,
     };
 
-    let end: ops::Bound<&usize> = range.end_bound();
-    let end = match end {
+    let end = match range.end_bound() {
         ops::Bound::Included(end) => {
             end.checked_add(1).unwrap_or_else(|| slice_end_index_overflow_fail())
         }
@@ -732,6 +730,59 @@ where
     ops::Range { start, end }
 }
 
+/// Performs bounds-checking of a range without panicking.
+///
+/// This is a version of [`range`] that returns [`None`] instead of panicking.
+///
+/// # Examples
+///
+/// ```
+/// #![feature(slice_range)]
+///
+/// use std::slice;
+///
+/// let v = [10, 40, 30];
+/// assert_eq!(Some(1..2), slice::try_range(1..2, ..v.len()));
+/// assert_eq!(Some(0..2), slice::try_range(..2, ..v.len()));
+/// assert_eq!(Some(1..3), slice::try_range(1.., ..v.len()));
+/// ```
+///
+/// Returns [`None`] when [`Index::index`] would panic:
+///
+/// ```
+/// #![feature(slice_range)]
+///
+/// use std::slice;
+///
+/// assert_eq!(None, slice::try_range(2..1, ..3));
+/// assert_eq!(None, slice::try_range(1..4, ..3));
+/// assert_eq!(None, slice::try_range(1..=usize::MAX, ..3));
+/// ```
+///
+/// [`Index::index`]: ops::Index::index
+#[unstable(feature = "slice_range", issue = "76393")]
+#[must_use]
+pub fn try_range<R>(range: R, bounds: ops::RangeTo<usize>) -> Option<ops::Range<usize>>
+where
+    R: ops::RangeBounds<usize>,
+{
+    let len = bounds.end;
+
+    let start = match range.start_bound() {
+        ops::Bound::Included(&start) => start,
+        ops::Bound::Excluded(start) => start.checked_add(1)?,
+        ops::Bound::Unbounded => 0,
+    };
+
+    let end = match range.end_bound() {
+        ops::Bound::Included(end) => end.checked_add(1)?,
+        ops::Bound::Excluded(&end) => end,
+        ops::Bound::Unbounded => len,
+    };
+
+    if start > end || end > len { None } else { Some(ops::Range { start, end }) }
+}
+
 /// Convert pair of `ops::Bound`s into `ops::Range` without performing any bounds checking and (in debug) overflow checking
 pub(crate) fn into_range_unchecked(
     len: usize,

core/src/slice/mod.rs

@@ -91,7 +91,7 @@ pub use sort::heapsort;
 pub use index::SliceIndex;
 
 #[unstable(feature = "slice_range", issue = "76393")]
-pub use index::range;
+pub use index::{range, try_range};
 
 #[stable(feature = "inherent_ascii_escape", since = "1.60.0")]
 pub use ascii::EscapeAscii;

std/src/sys/pal/unix/thread.rs

@@ -806,9 +806,9 @@ pub mod guard {
     #[cfg(any(
         target_os = "android",
         target_os = "freebsd",
+        target_os = "netbsd",
         target_os = "hurd",
         target_os = "linux",
-        target_os = "netbsd",
         target_os = "l4re"
     ))]
     unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
@@ -911,9 +911,10 @@ pub mod guard {
                         }
                     }) * page_size;
             Some(guard)
-        } else if cfg!(target_os = "openbsd") {
+        } else if cfg!(any(target_os = "openbsd", target_os = "netbsd")) {
             // OpenBSD stack already includes a guard page, and stack is
             // immutable.
+            // NetBSD stack includes the guard page.
             //
             // We'll just note where we expect rlimit to start
             // faulting, so our handler can report "stack overflow", and

std/src/sys/pal/windows/alloc.rs

@@ -6,6 +6,7 @@ use crate::ptr;
 use crate::sync::atomic::{AtomicPtr, Ordering};
 use crate::sys::c;
 use crate::sys::common::alloc::{realloc_fallback, MIN_ALIGN};
+use core::mem::MaybeUninit;
 
 #[cfg(test)]
 mod tests;
@@ -94,29 +95,30 @@ static HEAP: AtomicPtr<c_void> = AtomicPtr::new(ptr::null_mut());
 // a non-null handle returned by `GetProcessHeap`.
 #[inline]
 fn init_or_get_process_heap() -> c::HANDLE {
-    let heap = HEAP.load(Ordering::Relaxed);
-    if core::intrinsics::unlikely(heap.is_null()) {
-        // `HEAP` has not yet been successfully initialized
-        let heap = unsafe { GetProcessHeap() };
-        if !heap.is_null() {
-            // SAFETY: No locking is needed because within the same process,
-            // successful calls to `GetProcessHeap` will always return the same value, even on different threads.
-            HEAP.store(heap, Ordering::Release);
-
-            // SAFETY: `HEAP` contains a non-null handle returned by `GetProcessHeap`
-            heap
-        } else {
-            // Could not get the current process heap.
-            ptr::null_mut()
-        }
-    } else {
+    // `HEAP` has not yet been successfully initialized
+    let heap = unsafe { GetProcessHeap() };
+    if !heap.is_null() {
+        // SAFETY: No locking is needed because within the same process,
+        // successful calls to `GetProcessHeap` will always return the same value, even on different threads.
+        HEAP.store(heap, Ordering::Release);
+
         // SAFETY: `HEAP` contains a non-null handle returned by `GetProcessHeap`
         heap
+    } else {
+        // Could not get the current process heap.
+        ptr::null_mut()
     }
 }
 
+/// This is outlined from `process_heap_alloc` so that `process_heap_alloc`
+/// does not need any stack allocations.
 #[inline(never)]
-fn process_heap_alloc(flags: c::DWORD, dwBytes: c::SIZE_T) -> c::LPVOID {
+#[cold]
+extern "C" fn process_heap_init_and_alloc(
+    _heap: MaybeUninit<c::HANDLE>, // We pass this argument to match the ABI of `HeapAlloc`
+    flags: c::DWORD,
+    dwBytes: c::SIZE_T,
+) -> c::LPVOID {
     let heap = init_or_get_process_heap();
     if core::intrinsics::unlikely(heap.is_null()) {
         return ptr::null_mut();
@@ -125,6 +127,21 @@ fn process_heap_alloc(flags: c::DWORD, dwBytes: c::SIZE_T) -> c::LPVOID {
     unsafe { HeapAlloc(heap, flags, dwBytes) }
 }
 
+#[inline(never)]
+fn process_heap_alloc(
+    _heap: MaybeUninit<c::HANDLE>, // We pass this argument to match the ABI of `HeapAlloc`,
+    flags: c::DWORD,
+    dwBytes: c::SIZE_T,
+) -> c::LPVOID {
+    let heap = HEAP.load(Ordering::Relaxed);
+    if core::intrinsics::likely(!heap.is_null()) {
+        // SAFETY: `heap` is a non-null handle returned by `GetProcessHeap`.
+        unsafe { HeapAlloc(heap, flags, dwBytes) }
+    } else {
+        process_heap_init_and_alloc(MaybeUninit::uninit(), flags, dwBytes)
+    }
+}
+
 // Get a non-null handle to the default heap of the current process.
 // SAFETY: `HEAP` must have been successfully initialized.
 #[inline]
@@ -148,12 +165,12 @@ unsafe fn allocate(layout: Layout, zeroed: bool) -> *mut u8 {
 
     if layout.align() <= MIN_ALIGN {
         // The returned pointer points to the start of an allocated block.
-        process_heap_alloc(flags, layout.size()) as *mut u8
+        process_heap_alloc(MaybeUninit::uninit(), flags, layout.size()) as *mut u8
     } else {
         // Allocate extra padding in order to be able to satisfy the alignment.
         let total = layout.align() + layout.size();
 
-        let ptr = process_heap_alloc(flags, total) as *mut u8;
+        let ptr = process_heap_alloc(MaybeUninit::uninit(), flags, total) as *mut u8;
         if ptr.is_null() {
             // Allocation has failed.
             return ptr::null_mut();

std/src/sys/pal/windows/c.rs

@@ -344,6 +344,7 @@ compat_fn_with_fallback! {
 
     // >= Win8 / Server 2012
     // https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime
+    #[cfg(target_vendor = "win7")]
     pub fn GetSystemTimePreciseAsFileTime(lpsystemtimeasfiletime: *mut FILETIME) -> () {
         GetSystemTimeAsFileTime(lpsystemtimeasfiletime)
     }

std/src/sys/pal/windows/c/bindings.txt

@@ -2476,6 +2476,7 @@ Windows.Win32.System.Pipes.PIPE_WAIT
 Windows.Win32.System.SystemInformation.GetSystemDirectoryW
 Windows.Win32.System.SystemInformation.GetSystemInfo
 Windows.Win32.System.SystemInformation.GetSystemTimeAsFileTime
+Windows.Win32.System.SystemInformation.GetSystemTimePreciseAsFileTime
 Windows.Win32.System.SystemInformation.GetWindowsDirectoryW
 Windows.Win32.System.SystemInformation.PROCESSOR_ARCHITECTURE
 Windows.Win32.System.SystemInformation.SYSTEM_INFO

std/src/sys/pal/windows/c/windows_sys.rs

@@ -345,6 +345,10 @@ extern "system" {
     pub fn GetSystemTimeAsFileTime(lpsystemtimeasfiletime: *mut FILETIME) -> ();
 }
 #[link(name = "kernel32")]
+extern "system" {
+    pub fn GetSystemTimePreciseAsFileTime(lpsystemtimeasfiletime: *mut FILETIME) -> ();
+}
+#[link(name = "kernel32")]
 extern "system" {
     pub fn GetTempPathW(nbufferlength: u32, lpbuffer: PWSTR) -> u32;
 }