Rollup merge of rust-lang#154004 - GrigorenkoPV:alignment/as_nonzero_usize, r=scottmcm

`Alignment`: move from `ptr` to `mem` and rename `as_nonzero` to `as_nonzero_usize`

- tracking issue: rust-lang#102070
- split off from rust-lang#153261

Author: JonathanBrouwer

compiler/rustc_builtin_macros/src/global_allocator.rs

@@ -180,7 +180,7 @@ impl AllocFnFactory<'_, '_> {
     }
 
     fn ptr_alignment(&self) -> Box<Ty> {
-        let path = self.cx.std_path(&[sym::ptr, sym::Alignment]);
+        let path = self.cx.std_path(&[sym::mem, sym::Alignment]);
         let path = self.cx.path(self.span, path);
         self.cx.ty_path(path)
     }

compiler/rustc_data_structures/src/aligned.rs

@@ -1,4 +1,7 @@
 use std::marker::PointeeSized;
+#[cfg(not(bootstrap))]
+use std::mem::Alignment;
+#[cfg(bootstrap)]
 use std::ptr::Alignment;
 
 /// Returns the ABI-required minimum alignment of a type in bytes.

compiler/rustc_data_structures/src/tagged_ptr.rs

@@ -55,7 +55,12 @@ pub unsafe trait Tag: Copy {
 /// Returns the number of bits available for use for tags in a pointer to `T`
 /// (this is based on `T`'s alignment).
 pub const fn bits_for<T: ?Sized + Aligned>() -> u32 {
-    crate::aligned::align_of::<T>().as_nonzero().trailing_zeros()
+    let alignment = crate::aligned::align_of::<T>();
+    #[cfg(bootstrap)]
+    let alignment = alignment.as_nonzero();
+    #[cfg(not(bootstrap))]
+    let alignment = alignment.as_nonzero_usize();
+    alignment.trailing_zeros()
 }
 
 /// Returns the correct [`Tag::BITS`] constant for a set of tag values.

compiler/rustc_middle/src/ty/list.rs

@@ -264,7 +264,10 @@ unsafe impl<H: DynSync, T: DynSync> DynSync for RawList<H, T> {}
 // Layouts of `ListSkeleton<H, T>` and `RawList<H, T>` are the same, modulo opaque tail,
 // thus aligns of `ListSkeleton<H, T>` and `RawList<H, T>` must be the same.
 unsafe impl<H, T> Aligned for RawList<H, T> {
+    #[cfg(bootstrap)]
     const ALIGN: ptr::Alignment = align_of::<ListSkeleton<H, T>>();
+    #[cfg(not(bootstrap))]
+    const ALIGN: mem::Alignment = align_of::<ListSkeleton<H, T>>();
 }
 
 /// A [`List`] that additionally stores type information inline to speed up

compiler/rustc_span/src/symbol.rs

@@ -1227,6 +1227,7 @@ symbols! {
         maybe_uninit,
         maybe_uninit_uninit,
         maybe_uninit_zeroed,
+        mem,
         mem_align_const,
         mem_discriminant,
         mem_drop,

library/alloc/src/alloc.rs

@@ -5,7 +5,8 @@
 #[stable(feature = "alloc_module", since = "1.28.0")]
 #[doc(inline)]
 pub use core::alloc::*;
-use core::ptr::{self, Alignment, NonNull};
+use core::mem::Alignment;
+use core::ptr::{self, NonNull};
 use core::{cmp, hint};
 
 unsafe extern "Rust" {

library/alloc/src/raw_vec/mod.rs

@@ -5,8 +5,8 @@
 // run the tests. See the comment there for an explanation why this is the case.
 
 use core::marker::{Destruct, PhantomData};
-use core::mem::{ManuallyDrop, MaybeUninit, SizedTypeProperties};
-use core::ptr::{self, Alignment, NonNull, Unique};
+use core::mem::{Alignment, ManuallyDrop, MaybeUninit, SizedTypeProperties};
+use core::ptr::{self, NonNull, Unique};
 use core::{cmp, hint};
 
 #[cfg(not(no_global_oom_handling))]
@@ -570,7 +570,7 @@ const impl<A: [const] Allocator + [const] Destruct> RawVecInner<A> {
 impl<A: Allocator> RawVecInner<A> {
     #[inline]
     const fn new_in(alloc: A, align: Alignment) -> Self {
-        let ptr = Unique::from_non_null(NonNull::without_provenance(align.as_nonzero()));
+        let ptr = Unique::from_non_null(NonNull::without_provenance(align.as_nonzero_usize()));
         // `cap: 0` means "unallocated". zero-sized types are ignored.
         Self { ptr, cap: ZERO_CAP, alloc }
     }

library/alloc/src/rc.rs

@@ -252,7 +252,7 @@ use core::intrinsics::abort;
 #[cfg(not(no_global_oom_handling))]
 use core::iter;
 use core::marker::{PhantomData, Unsize};
-use core::mem::{self, ManuallyDrop};
+use core::mem::{self, Alignment, ManuallyDrop};
 use core::num::NonZeroUsize;
 use core::ops::{CoerceUnsized, Deref, DerefMut, DerefPure, DispatchFromDyn, LegacyReceiver};
 #[cfg(not(no_global_oom_handling))]
@@ -261,7 +261,7 @@ use core::panic::{RefUnwindSafe, UnwindSafe};
 #[cfg(not(no_global_oom_handling))]
 use core::pin::Pin;
 use core::pin::PinCoerceUnsized;
-use core::ptr::{self, Alignment, NonNull, drop_in_place};
+use core::ptr::{self, NonNull, drop_in_place};
 #[cfg(not(no_global_oom_handling))]
 use core::slice::from_raw_parts_mut;
 use core::{borrow, fmt, hint};

library/alloc/src/sync.rs

@@ -19,14 +19,14 @@ use core::intrinsics::abort;
 #[cfg(not(no_global_oom_handling))]
 use core::iter;
 use core::marker::{PhantomData, Unsize};
-use core::mem::{self, ManuallyDrop};
+use core::mem::{self, Alignment, ManuallyDrop};
 use core::num::NonZeroUsize;
 use core::ops::{CoerceUnsized, Deref, DerefMut, DerefPure, DispatchFromDyn, LegacyReceiver};
 #[cfg(not(no_global_oom_handling))]
 use core::ops::{Residual, Try};
 use core::panic::{RefUnwindSafe, UnwindSafe};
 use core::pin::{Pin, PinCoerceUnsized};
-use core::ptr::{self, Alignment, NonNull};
+use core::ptr::{self, NonNull};
 #[cfg(not(no_global_oom_handling))]
 use core::slice::from_raw_parts_mut;
 use core::sync::atomic::Ordering::{Acquire, Relaxed, Release};

library/core/src/alloc/layout.rs

@@ -6,8 +6,8 @@
 
 use crate::error::Error;
 use crate::intrinsics::{unchecked_add, unchecked_mul, unchecked_sub};
-use crate::mem::SizedTypeProperties;
-use crate::ptr::{Alignment, NonNull};
+use crate::mem::{Alignment, SizedTypeProperties};
+use crate::ptr::NonNull;
 use crate::{assert_unsafe_precondition, fmt, mem};
 
 /// Layout of a block of memory.
@@ -268,7 +268,7 @@ impl Layout {
     #[must_use]
     #[inline]
     pub const fn dangling_ptr(&self) -> NonNull<u8> {
-        NonNull::without_provenance(self.align.as_nonzero())
+        NonNull::without_provenance(self.align.as_nonzero_usize())
     }
 
     /// Creates a layout describing the record that can hold a value