Add a callback that allows compiler consumers to override queries.
This pull request adds an additional callback that allows compiler consumers such as Prusti and MIRAI to override queries. My hope is that in this way it will be possible to get access to the internal compiler information (e.g. borrow checker) without major changes to the compiler.
This pull request is work in progress because I am still testing if I can get the information which I need.
cc @nikomatsakis
r? @oli-obk
add Result::map_or
This PR adds this API to make it consistent with `Option::map_or`.
```rust
impl<T, E> Result<T, E> {
pub fn map_or<U, F: FnOnce(T) -> U>(self, default: U, f: F) -> U {
match self {
Ok(t) => f(t),
Err(_) => default,
}
}
}
```
This API is very small. We already has a similar API for `Option::map_or`.
add raw ptr variant of UnsafeCell::get
This has come up recently in https://github.com/rust-lang/rust/pull/66051 (Cc @Centril @pitdicker) as well as in discussion with @nikomatsakis and in unrelated discussion with @withoutboats.
docs: Fix link to BufWriter::flush
One of the links in the docs was being rendered as a literal
open-bracket followed by a single quote, instead of being transformed
into a link. Fix it to match the link earlier in the same paragraph.
Fix documentation for `Iterator::count()`.
The documentation of std::core::Iterator::count() stated that the number returned is the number of times `next` is called on the iterator. However this is not true as the number of times `next` is called is exactly one plus the number returned by `count()`.
proposal for BTreeMap/Set min/max, #62924
- Which pair of names: #62924 lists the existing possibilities min/max, first/last, (EDIT) front/back, peek(/peek_back?). Iterators have next/next_back or next/last. I'm slightly in favour of first/last because min/max might suggest they search over the entire map, and front/back pretends they are only about position.
- Return key only instead of pair like iterator does?
- If not, then keep the _key_value suffix? ~~Also provide variant with mutable value? But there is no such variant for get_key_value.~~
- Look for and upgrade more usages of `.iter().next()` and such in the libraries? I only upgraded the ones I contributed myself, all very recently.
Add hooks for Miri panic unwinding
This commits adds in some additional hooks to allow Miri to properly
handle panic unwinding. None of this should have any impact on CTFE mode
This supports https://github.com/rust-lang/miri/pull/693
Fix MIR lowering evaluation order and soundness bug
* Fixes a soundness issue with built-in index operations
* Ensures correct evaluation order of assignment expressions where the RHS is a FRU or is a use of a local of reference type.
* Removes an unnecessary symbol to string conversion
closes#65909closes#65910
support issue = "none" in unstable attributes
This works towards fixing #41260.
This PR allows the use of `issue = "none"` in unstable attributes and makes changes to internally store the issue number as an `Option<NonZeroU32>`. For example:
```rust
#[unstable(feature = "unstable_test_feature", issue = "none")]
fn unstable_issue_none() {}
```
It was not made optional because feedback seen here #60860 suggested that people might forget the issue field if it was optional.
I could not remove the current uses of `issue = "0"` (of which there are a lot) because the stage 0 compiler expects the old syntax. Once this is available in the stage 0 compiler we can replace all uses of `"0"` with `"none"` and no longer allow `"0"`. This is my first time contributing, so I'm not sure what the protocol is with two-part things like this, so some guidance would be appreciated.
r? @varkor
Fix HashSet::union performance
Consider this example: small_set = 0..2, large_set = 0..1000.
To efficiently compute the union of these sets, we should
* take all elements of the larger set
* for each element of the smaller set check it is not in the larger set
This is exactly what this commit does.
This particular optimization was implemented a year ago, but the
author mistaken `<` and `>`.
Fix error message about exported symbols from proc-macro crates
Someone forgot to update the error message after `#[proc_macro]` and
`#[proc_macro_attribute]` were stabilized.
make the error message more readable
When I type it wrong e.g. `--stage --bless`, missing a number here, this change would make it more explicit what's going wrong here.
Drop long-section-names linker workaround for windows-gnu
If we can trust objdump Rust doesn't emit sections loaded at runtime longer than 8 characters on windows-gnu (but still does on linux-gnu), debug sections are not affected by that limit.
I've ran tests and built few crates using exactly the same mingw-w64 version as Rusts CI just fine using **x86_64** toolchain.
The motivation for this change is making LLD work (it doesn't support `--enable-long-section-names`) with this target without hacks.
Bit of history:
The behaviour of LD changed in Binutils 2.20 released on 2009-10-16 and `--enable-long-section-names` was added to return to the old non conformant behaviour. Looking at the comment I can only guess there was a bug fixed in newer versions.
This workaround was added in https://github.com/rust-lang/rust/pull/13315 half a decade ago.
remove vestigial comments referring to defunct numeric trait hierarchy
I've been poking around the numeric trait hierarchy and also some of the actual numeric type implementations.
This is a small change but a matter of effective communication. I looked for other related references and saw none.
Refactor slice pattern usefulness checking
As a follow up to https://github.com/rust-lang/rust/pull/65874, this PR changes how variable-length slice patterns are handled in usefulness checking. The objectives are: cleaning up that code to make it easier to understand, and paving the way to handling fixed-length slices more cleverly too, for https://github.com/rust-lang/rust/issues/53820.
Before this, variable-length slice patterns were eagerly expanded into a union of fixed-length slices. Now they have their own special constructor, which allows expanding them a bit more lazily.
As a nice side-effect, this improves diagnostics.
This PR shows a slight performance improvement, mostly due to https://github.com/rust-lang/rust/pull/66129/commits/149792b6080f40875c0072aae378a0eb31d23df0. This will probably have to be reverted in some way when we implement or-patterns.
An expression like `x[1][{ x = y; 2}]` would perform the bounds check
for the inner index operation before evaluating the outer index. This
would allow out of bounds memory accesses.
