Rollup of 9 pull requests

compiler/rustc_codegen_cranelift/example/mini_core.rs

@@ -8,6 +8,7 @@
     rustc_attrs,
     transparent_unions,
     auto_traits,
+    freeze_impls,
     thread_local
 )]
 #![no_core]

compiler/rustc_codegen_gcc/example/mini_core.rs

@@ -1,6 +1,6 @@
 #![feature(
     no_core, lang_items, intrinsics, unboxed_closures, type_ascription, extern_types,
-    decl_macro, rustc_attrs, transparent_unions, auto_traits,
+    decl_macro, rustc_attrs, transparent_unions, auto_traits, freeze_impls,
     thread_local
 )]
 #![no_core]

compiler/rustc_feature/src/unstable.rs

@@ -471,6 +471,8 @@ declare_features! (
     (unstable, fn_align, "1.53.0", Some(82232)),
     /// Support delegating implementation of functions to other already implemented functions.
     (incomplete, fn_delegation, "1.76.0", Some(118212)),
+    /// Allows impls for the Freeze trait.
+    (internal, freeze_impls, "CURRENT_RUSTC_VERSION", Some(121675)),
     /// Allows defining gen blocks and `gen fn`.
     (unstable, gen_blocks, "1.75.0", Some(117078)),
     /// Infer generic args for both consts and types.

compiler/rustc_hir_analysis/src/coherence/mod.rs

@@ -10,6 +10,7 @@ use rustc_errors::{codes::*, struct_span_code_err};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
+use rustc_session::parse::feature_err;
 use rustc_span::{sym, ErrorGuaranteed};
 use rustc_trait_selection::traits;
 
@@ -49,6 +50,19 @@ fn enforce_trait_manually_implementable(
 ) -> Result<(), ErrorGuaranteed> {
     let impl_header_span = tcx.def_span(impl_def_id);
 
+    if tcx.lang_items().freeze_trait() == Some(trait_def_id) {
+        if !tcx.features().freeze_impls {
+            feature_err(
+                &tcx.sess,
+                sym::freeze_impls,
+                impl_header_span,
+                "explicit impls for the `Freeze` trait are not permitted",
+            )
+            .with_span_label(impl_header_span, format!("impl of `Freeze` not allowed"))
+            .emit();
+        }
+    }
+
     // Disallow *all* explicit impls of traits marked `#[rustc_deny_explicit_impl]`
     if trait_def.deny_explicit_impl {
         let trait_name = tcx.item_name(trait_def_id);

compiler/rustc_lint/src/internal.rs

@@ -409,9 +409,8 @@ impl LateLintPass<'_> for Diagnostics {
             }
         };
 
-        // Does the callee have a `impl Into<{D,Subd}iagMessage>` parameter? (There should be at
-        // most one.)
-        let mut impl_into_diagnostic_message_param = None;
+        // Does the callee have one or more `impl Into<{D,Subd}iagMessage>` parameters?
+        let mut impl_into_diagnostic_message_params = vec![];
         let fn_sig = cx.tcx.fn_sig(def_id).instantiate_identity().skip_binder();
         let predicates = cx.tcx.predicates_of(def_id).instantiate_identity(cx.tcx).predicates;
         for (i, &param_ty) in fn_sig.inputs().iter().enumerate() {
@@ -425,20 +424,14 @@ impl LateLintPass<'_> for Diagnostics {
                         && let ty1 = trait_ref.args.type_at(1)
                         && is_diag_message(ty1)
                     {
-                        if impl_into_diagnostic_message_param.is_some() {
-                            cx.tcx.dcx().span_bug(
-                                span,
-                                "can't handle multiple `impl Into<{D,Sub}iagMessage>` params",
-                            );
-                        }
-                        impl_into_diagnostic_message_param = Some((i, p.name));
+                        impl_into_diagnostic_message_params.push((i, p.name));
                     }
                 }
             }
         }
 
         // Is the callee interesting?
-        if !has_attr && impl_into_diagnostic_message_param.is_none() {
+        if !has_attr && impl_into_diagnostic_message_params.is_empty() {
             return;
         }
 
@@ -481,7 +474,7 @@ impl LateLintPass<'_> for Diagnostics {
         // Calls to methods with an `impl Into<{D,Subd}iagMessage>` parameter must be passed an arg
         // with type `{D,Subd}iagMessage` or `impl Into<{D,Subd}iagMessage>`. Otherwise, emit an
         // `UNTRANSLATABLE_DIAGNOSTIC` lint.
-        if let Some((param_i, param_i_p_name)) = impl_into_diagnostic_message_param {
+        for (param_i, param_i_p_name) in impl_into_diagnostic_message_params {
             // Is the arg type `{Sub,D}iagMessage`or `impl Into<{Sub,D}iagMessage>`?
             let arg_ty = call_tys[param_i];
             let is_translatable = is_diag_message(arg_ty)

compiler/rustc_span/src/symbol.rs

@@ -864,6 +864,7 @@ symbols! {
         format_placeholder,
         format_unsafe_arg,
         freeze,
+        freeze_impls,
         freg,
         frem_algebraic,
         frem_fast,

config.example.toml

@@ -842,6 +842,17 @@
 # See that option for more info.
 #codegen-backends = rust.codegen-backends (array)
 
+# This is a "runner" to pass to `compiletest` when executing tests. Tests will
+# execute this tool where the binary-to-test is passed as an argument. Can
+# be useful for situations such as when WebAssembly is being tested and a
+# runtime needs to be configured. This value is similar to
+# Cargo's `CARGO_$target_RUNNER` configuration.
+#
+# This configuration is a space-separated list of arguments so `foo bar` would
+# execute the program `foo` with the first argument as `bar` and the second
+# argument as the test binary.
+#runner = <none> (string)
+
 # =============================================================================
 # Distribution options
 #

library/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))
         }
     }

library/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")]

library/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)]

library/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,

library/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,

library/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;

library/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

library/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();