Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
This code was added in 9dc5dfb975
and 704050da23 because the browser-
native checkbox was `display: none`, breaking native keyboard
accessibility.
The native checkbox is now merely `appearance: none`, which does
not turn off [behavior semantics], so JavaScript to
reimplement it isn't needed any more.
[behavior semantics]: https://w3c.github.io/csswg-drafts/css-ui/#appearance-semantics
I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways
d19b64fb54/library/core/src/slice/iter/macros.rs (L76-L93)
so started making this PR, then added a few more I found since I was already making changes anyway.
* There's no need to call `history.replaceState` right before
calling `searchState.hideResults`, which already does it.
* There's no need to implement hiding search results when that
is already implemented.
Rollup of 5 pull requests
Successful merges:
- #110333 (rustc_metadata: Split `children` into multiple tables)
- #110501 (rustdoc: fix ICE from rustc_resolve and librustdoc parse divergence)
- #110608 (Specialize some `io::Read` and `io::Write` methods for `VecDeque<u8>` and `&[u8]`)
- #110632 (Panic instead of truncating if the incremental on-disk cache is too big)
- #110633 (More `mem::take` in `library`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Ensure mir_drops_elaborated_and_const_checked when requiring codegen.
mir_drops_elaborated_and_const_checked may emit errors while codegen has started, and the compiler would exit leaving object code files around.
Found by `@cuviper` in https://github.com/rust-lang/rust/issues/109731
`provide_sorted_batch` in core is incorrectly marked with
`#[cfg(not(no_global_oom_handling))]` which prevents core
from building with the cfg enabled.
Nothing in core allocates memory including this function, so
the `cfg` gate is incorrect.
Deduplicate unreachable blocks, for real this time
In https://github.com/rust-lang/rust/pull/106428 (in particular 41eda69516) we noticed that inlining `unreachable_unchecked` can produce duplicate unreachable blocks. So we improved two MIR optimizations: `SimplifyCfg` was given a simplify to deduplicate unreachable blocks, then `InstCombine` was given a combiner to deduplicate switch targets that point at the same block. The problem is that change doesn't actually work.
Our current pass order is
```
SimplifyCfg (does nothing relevant to this situation)
Inline (produces multiple unreachable blocks)
InstCombine (doesn't do anything here, oops)
SimplifyCfg (produces the duplicate SwitchTargets that InstCombine is looking for)
```
So in here, I have factored out the specific function from `InstCombine` and placed it inside the simplify that produces the case it is looking for. This should ensure that it runs in the scenario it was designed for.
Fixes https://github.com/rust-lang/rust/issues/110551
r? `@cjgillot`
Panic instead of truncating if the incremental on-disk cache is too big
It seems _unlikely_ that anyone would hit this truncation, but if this `as` does actually truncate, that seems incredibly bad.
Specialize some `io::Read` and `io::Write` methods for `VecDeque<u8>` and `&[u8]`
This improves implementation of:
- `<&[u8]>::read_to_string`
- `VecDeque<u8>::read_to_end`
- `VecDeque<u8>::read_to_string`
- `VecDeque<u8>::write_vectored`
rustc_metadata: Split `children` into multiple tables
instead of merging everything into a single bag.
If it's acceptable from performance point of view, then it's more clear to keep this stuff organized more in accordance with its use.
instead of merging everything into a single bag.
If it's acceptable from performance point of view, then it's more clear to keep this stuff organized more in accordance with its use.
Added byte position range for `proc_macro::Span`
Currently, the [`Debug`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#impl-Debug-for-Span) implementation for [`proc_macro::Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) calls the debug function implemented in the trait implementation of `server::Span` for the type `Rustc` in the `rustc-expand` crate.
The current implementation, of the referenced function, looks something like this:
```rust
fn debug(&mut self, span: Self::Span) -> String {
if self.ecx.ecfg.span_debug {
format!("{:?}", span)
} else {
format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
}
}
```
It returns the byte position of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) as an interpolated string.
Because this is currently the only way to get a spans position in the file, I might lead someone, who is interested in this information, to parsing this interpolated string back into a range of bytes, which I think is a very non-rusty way.
The proposed `position()`, method implemented in this PR, gives the ability to directly get this info.
It returns a [`std::ops::Range`](https://doc.rust-lang.org/std/ops/struct.Range.html#) wrapping the lowest and highest byte of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#).
I put it behind the `proc_macro_span` feature flag because many of the other functions that have a similar footprint also are annotated with it, I don't actually know if this is right.
It would be great if somebody could take a look at this, thank you very much in advanced.
