Migrate `rustc_ty_utils` to `SessionDiagnostic`
I have migrated the `rustc_ty_utils` crate to use `SessionDiagnostic`, motivated by the [recent blog post about the diagnostic translation effort](https://blog.rust-lang.org/inside-rust/2022/08/16/diagnostic-effort.html).
This is my first PR to the Rust repository, so if I have missed anything, or anything needs to be changed, please let me know! 😄
`@rustbot` label +A-translation
Migrate ast lowering to session diagnostic
I migrated the whole rustc_ast_lowering crate to session diagnostic *except* the for the use of `span_fatal` at /compiler/rustc_ast_lowering/src/expr.rs#L1268 because `#[fatal(...)]` is not yet supported (see https://github.com/rust-lang/rust/pull/100694).
interpret: remove support for uninitialized scalars
With Miri no longer supporting `-Zmiri-allow-uninit-numbers`, we no longer need to support storing uninit data in a `Scalar`. We anyway already only use this representation for types with *initialized* `Scalar` layout (and we have to, due to partial initialization), so let's get rid of the `ScalarMaybeUninit` type entirely.
I tried to stage this into meaningful commits, but the one that changes `read_immediate` to always trigger UB on uninit is the largest chunk of the PR and I don't see how it could be subdivided.
Fixes https://github.com/rust-lang/miri/issues/2187
r? `@oli-obk`
Fixes#100994
This selector was added in c7312fbae4979c6d4fdfbd1f55a71cd47d82a480.
The bug can be seen at <https://doc.rust-lang.org/1.27.0/alloc/slice/trait.SliceIndex.html#foreign-impls>.
This rule was added to help with a `<table>` that was used for displaying the
function signature [src] lockup. That lockup was changed in
34bd2b845b3acd84c5a9bddae3ff8081c19ec5e9 to use flexbox instead, leaving this
selector unused (at least, for its original purpose).
session: stabilize split debuginfo on linux
Stabilize the `-Csplit-debuginfo` flag...
- ...on Linux for all values of the flag. Split DWARF has been implemented for a few months, hasn't had any bug reports and has had some promising benchmarking for incremental debug build performance.
- ..on other platforms for the default value. It doesn't make any sense that `-Csplit-debuginfo=packed` is unstable on Windows MSVC when that's the default behaviour, but keep the other values unstable.
This CSS seems to have become obsolete with the move to `<details>` tags,
and its corresponding JavaScript was removed in aee054d05d8b795d35c0b448a4b731b6507aa459
rustdoc: remove unused CSS for `.variants_table`
Continuation of #100938 and #101010. This rule was added to support the old, table-based style for displaying enum variants, which are now displayed using headers and paragraphs.
Fix doc cfg on reexports
Fixes#83428.
The problem was that the newly inlined item cfg propagation was not working since its real parent is different than its current one.
For the implementation, I decided to put it directly into `CfgPropagation` instead of inside `inline.rs` because I thought it would be simpler to maintain and to not forget if new kind of items are added if it's all done in one place.
r? `@notriddle`
Reduce right-side DOM size
This is another follow-up of https://github.com/rust-lang/rust/pull/100429 but not in code blocks this time.
So the idea is: if there is only one element in the `.rightside` element, there is no need to wrap it, we can just create one node.
On each page, I run this JS: `document.getElementsByTagName('*').length`. Important to note: the bigger the number of elements inside the page, the greater the gain. It also doesn't work very nicely on std docs because there are a lot of version annotations. So with this PR, It allows to get the following results:
| file name | before this PR | with this PR | diff |
|-|-|-|-|
| std/default/trait.Default.html | 2189 | 1331 | 39.2% |
| std/vec/struct.Vec.html | 14073 | 13842 | 1.7% |
| std/fmt/trait.Debug.html | 5313 | 4907 | 7.7% |
| std/ops/trait.Index.html | 642 | 630 | 1.9% |
| gtk4/WidgetExt | 3269 | 3061 | 6.4% |
You can test it [here](https://rustdoc.crud.net/imperio/reduce-rightsize-dom-size/gtk4/prelude/trait.WidgetExt.html).
r? `@notriddle`
BTree: evaluate static type-related check at compile time
`assert`s like the ones replaced here would only go off when you run the right test cases, if the code were ever incorrectly changed such that rhey would trigger. But [inspired on a nice forum question](https://users.rust-lang.org/t/compile-time-const-generic-parameter-check/69202), they can be checked at compile time.
Avoid reporting overflow in `is_impossible_method`
Fixes#100620
We're evaluating a new predicate in a different param-env than it was checked during typeck, so be more careful about handling overflow errors. Instead of using `FulfillmentCtxt`, using `InferCtxt::evaluate_obligation` by itself will give us back the overflow error, so we can throw it away properly.
This may give us more false-positives, but it doesn't regress the `<HashMap as Iterator>::rev` example that originally motivated adding `is_impossible_method` in the first place.
rustdoc: remove unused CSS for `.multi-column`
As a sanity check, [this tool] can be used to run a CSS query across an HTML tree to detect if a selector ever matches (I use compiler-docs and std docs). This isn't good enough, because I also need to account for JavaScript, but this class is never mentioned in any of the JS files, either.
According to [blame], this class was added when rustdoc was first written, and, as far as I can tell, was never actually used.
[this tool]: https://gitlab.com/notriddle/html-scanner
[blame]: 4d45b0745a/src/librustdoc/html/static/css/rustdoc.css (L753-L761)
Reduce code size of `assert_matches_failed`
Using `write_str` instead of `<str as Display>::fmt` avoids the `pad` function which is very expensive to have in size-constrained code.
make slice::{split_at,split_at_unchecked} const functions
Now that `slice::from_raw_parts` is const in stable 1.64, it makes sense to have `split_at` const as well, otherwise unsafe code is required to achieve a const equivalent.
Elaborate all box dereferences in `ElaborateBoxDerefs`
so that it is the only pass responsible for elaboration, instead of
splitting this responsibility between the `StateTransform` and
`ElaborateBoxDerefs`.
distinguish the method and associated function diagnostic information
Methods are defined within the context of a struct and their first parameter is always self
Associated functions don’t take self as a parameter
```
modified: compiler/rustc_typeck/src/check/method/suggest.rs
modified: src/test/ui/auto-ref-slice-plus-ref.stderr
modified: src/test/ui/block-result/issue-3563.stderr
modified: src/test/ui/issues/issue-28344.stderr
modified: src/test/ui/suggestions/dont-suggest-pin-array-dot-set.stderr
modified: src/test/ui/suggestions/suggest-methods.stderr
modified: src/test/ui/traits/trait-upcasting/subtrait-method.stderr
```
Currently they try to be very precise. But they are wrong, i.e. they
don't match what's happening in the loop below. This code isn't hot
enough for it to matter that much.
is_whitespace() performance improvements
This is my first rust PR, so if I miss anything obvious please let me know and I'll do my best to fix it.
This was a bit more of a challenge than I realized because, while I made working code locally and tested it against the native `is_whitespace()`, this PR required changing `src/tools/unicode-table-generator`, the code that generated the code.
I have benchmarked this locally, using criterion, and have seen meaningful performance improvements. I can add those outputs to this if you'd like, but am guessing that the perf run that `@fmease` recommended is what's needed.
I have run ` ./x.py test --stage 0 library/std` after building it locally after executing `./x.py build library`. I didn't try to build the whole compiler, but maybe I should have - any guidance would be appreciated.
If this general approach makes sense, I'll take a look at some other candidate categories, e.g., `Cc`, in the future.
Oh, and I wasn't sure whether the generated code should be included in this PR or not. I did include it.
