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Replace `WriteCloneIntoRaw` with `CloneToUninit`. · rust-lang/rust@a9a4830

5 files changed

lines changed

Original file line numberDiff line numberDiff line change

@@ -424,29 +424,3 @@ pub mod __alloc_error_handler {

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}

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}

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}

427-
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#[cfg(not(no_global_oom_handling))]

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/// Specialize clones into pre-allocated, uninitialized memory.

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/// Used by `Box::clone` and `Rc`/`Arc::make_mut`.

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pub(crate) trait WriteCloneIntoRaw: Sized {

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unsafe fn write_clone_into_raw(&self, target: *mut Self);

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}

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#[cfg(not(no_global_oom_handling))]

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impl<T: Clone> WriteCloneIntoRaw for T {

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#[inline]

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default unsafe fn write_clone_into_raw(&self, target: *mut Self) {

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// Having allocated *first* may allow the optimizer to create

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// the cloned value in-place, skipping the local and move.

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unsafe { target.write(self.clone()) };

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}

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}

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#[cfg(not(no_global_oom_handling))]

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impl<T: Copy> WriteCloneIntoRaw for T {

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#[inline]

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unsafe fn write_clone_into_raw(&self, target: *mut Self) {

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// We can always copy in-place, without ever involving a local value.

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unsafe { target.copy_from_nonoverlapping(self, 1) };

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}

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}

Original file line numberDiff line numberDiff line change

@@ -188,6 +188,8 @@

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use core::any::Any;

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use core::async_iter::AsyncIterator;

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use core::borrow;

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#[cfg(not(no_global_oom_handling))]

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use core::clone::CloneToUninit;

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use core::cmp::Ordering;

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use core::error::Error;

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use core::fmt;

@@ -207,7 +209,7 @@ use core::slice;

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use core::task::{Context, Poll};

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#[cfg(not(no_global_oom_handling))]

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use crate::alloc::{handle_alloc_error, WriteCloneIntoRaw};

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use crate::alloc::handle_alloc_error;

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use crate::alloc::{AllocError, Allocator, Global, Layout};

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#[cfg(not(no_global_oom_handling))]

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use crate::borrow::Cow;

@@ -1346,7 +1348,7 @@ impl<T: Clone, A: Allocator + Clone> Clone for Box<T, A> {

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// Pre-allocate memory to allow writing the cloned value directly.

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let mut boxed = Self::new_uninit_in(self.1.clone());

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unsafe {

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(**self).write_clone_into_raw(boxed.as_mut_ptr());

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(**self).clone_to_uninit(boxed.as_mut_ptr());

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boxed.assume_init()

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}

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}

Original file line numberDiff line numberDiff line change

@@ -103,6 +103,7 @@

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#![feature(assert_matches)]

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#![feature(async_fn_traits)]

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#![feature(async_iterator)]

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#![feature(clone_to_uninit)]

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#![feature(coerce_unsized)]

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#![feature(const_align_of_val)]

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#![feature(const_box)]

Original file line numberDiff line numberDiff line change

@@ -249,6 +249,8 @@ use std::boxed::Box;

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use core::any::Any;

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use core::borrow;

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use core::cell::Cell;

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#[cfg(not(no_global_oom_handling))]

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use core::clone::CloneToUninit;

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use core::cmp::Ordering;

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use core::fmt;

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use core::hash::{Hash, Hasher};

@@ -268,8 +270,6 @@ use core::slice::from_raw_parts_mut;

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#[cfg(not(no_global_oom_handling))]

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use crate::alloc::handle_alloc_error;

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#[cfg(not(no_global_oom_handling))]

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use crate::alloc::WriteCloneIntoRaw;

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use crate::alloc::{AllocError, Allocator, Global, Layout};

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use crate::borrow::{Cow, ToOwned};

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#[cfg(not(no_global_oom_handling))]

@@ -1810,7 +1810,7 @@ impl<T: Clone, A: Allocator + Clone> Rc<T, A> {

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let mut rc = Self::new_uninit_in(this.alloc.clone());

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unsafe {

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let data = Rc::get_mut_unchecked(&mut rc);

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(**this).write_clone_into_raw(data.as_mut_ptr());

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(**this).clone_to_uninit(data.as_mut_ptr());

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*this = rc.assume_init();

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}

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} else if Rc::weak_count(this) != 0 {

Original file line numberDiff line numberDiff line change

@@ -10,6 +10,8 @@

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use core::any::Any;

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use core::borrow;

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#[cfg(not(no_global_oom_handling))]

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use core::clone::CloneToUninit;

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use core::cmp::Ordering;

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use core::fmt;

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use core::hash::{Hash, Hasher};

@@ -30,8 +32,6 @@ use core::sync::atomic::Ordering::{Acquire, Relaxed, Release};

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#[cfg(not(no_global_oom_handling))]

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use crate::alloc::handle_alloc_error;

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#[cfg(not(no_global_oom_handling))]

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use crate::alloc::WriteCloneIntoRaw;

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use crate::alloc::{AllocError, Allocator, Global, Layout};

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use crate::borrow::{Cow, ToOwned};

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use crate::boxed::Box;

@@ -2219,7 +2219,7 @@ impl<T: Clone, A: Allocator + Clone> Arc<T, A> {

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let mut arc = Self::new_uninit_in(this.alloc.clone());

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unsafe {

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let data = Arc::get_mut_unchecked(&mut arc);

2222-

(**this).write_clone_into_raw(data.as_mut_ptr());

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(**this).clone_to_uninit(data.as_mut_ptr());

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*this = arc.assume_init();

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}

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} else if this.inner().weak.load(Relaxed) != 1 {