The acronym is not descriptive unless one has seen it before.
* Rename the `oom` function to `handle_alloc_error`. It was **stabilized in 1.28**, so if we do this at all we need to land it this cycle.
* Rename `set_oom_hook` to `set_alloc_error_hook`
* Rename `take_oom_hook` to `take_alloc_error_hook`
Bikeshed: `alloc` v.s. `allocator`, `error` v.s. `failure`
As discussed in
https://github.com/rust-lang/rust/issues/49668#issuecomment-384893456
and subsequent, there are use-cases where the OOM handler needs to know
the size of the allocation that failed. The alignment might also be a
cause for allocation failure, so providing it as well can be useful.
Partial future-proofing for Box<T, A>
In some ways, this is similar to @eddyb's PR #47043 that went stale, but doesn't cover everything. Notably, this still leaves Box internalized as a pointer in places, so practically speaking, only ZSTs can be practically added to the Box type with the changes here (the compiler ICEs otherwise).
The Box type is not changed here, that's left for the future because I want to test that further first, but this puts things in place in a way that hopefully will make things easier.
As of now, Box only contains a Unique pointer, so this is the sole
argument to box_free. Consequently, we remove the code supporting
the previous box_free signature. We however keep the old definition
for bootstrapping purpose.
94d1970bba moved the alloc::allocator
module to core::heap, moving e.g. Alloc and Layout out of the alloc
crate. While alloc::heap reexports them, it's better to use them from
where they really come from.
Thew `_raw` prefix is included because the fact that `Box`’s ownership
semantics are "dissolved" or recreated seem more important than the exact
parameter type or return type.
After discussing [1] today with @pnkfelix and @Gankro,
we concluded that it’s ok for drop checking not to be much smarter
than the current `#[may_dangle]` design which requires an explicit
unsafe opt-in.
[1] https://github.com/rust-lang/rust/issues/27730#issuecomment-316432083
There are a few exceptions to the rule that Arc/Rc are immutable. Rather
than dig into the details, add "generally" to hint at this difference,
as it's kind of a distraction at this point in the docs.
Additionally, Arc's docs were slightly different here generally, so add
in both the existing language and the exception.
Fixes#44105
Implement downcast the like it exists for Box.
The implementation avoids using into_raw/from_raw, because the pointer
arithmetic which should cancel does not seem to optimize out at the
moment.
Since Rc<T> is never Send, only Rc<Any> and not Rc<Any + Send>
implements downcast.
Implements RFC 1845, adding implementations of:
* `From<&[T]>` for `Rc<[T]>`
* `From<&str>` for `Rc<str>`
* `From<String>` for `Rc<str>`
* `From<Box<T: ?Sized>>` for `Rc<T>`
* `From<Vec<T>>` for `Rc<[T]>`
* and likewise for `Arc<_>`
Also removes now-obsolete internal methods `Rc::__from_array` and
`Rc::__from_str`, replacing their use with `Rc::from`.
This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.
[RFC 1974]: https://github.com/rust-lang/rfcs/pull/197
The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.
cc #27389
This commit
* Refactors the collect_lib_features function to work in a
non-checking mode (no bad pointer needed, and list of
lang features).
* Introduces checking whether unstable/stable tags for a
given feature have inconsistent tracking issues.
* Fixes such inconsistencies throughout the codebase.
It was decided in the RFC discussion https://github.com/rust-lang/rfcs/pull/1954 to make the function call syntax Rc::clone(&foo) the idiomatic way to clone a reference counted pointer (over the method call syntax foo.clone(). This change updates the documentation of Rc, Arc and their respoective Weak pointers to reflect it and bring more exposure to the existence of the function call syntax.
this avoids parsing item attributes on each call to `item_attrs`, which takes
off 33% (!) of translation time and 50% (!) of trans-item collection time.
