[win][arm64] Remove 'Arm64 Hazard' undocumented MSVC option and instead disable problematic test
PR #140758 added the undocumented `/arm64hazardfree` MSVC linker flag to work around a test failure where LLVM generated code that would trip a hazard in an outdated ARM processor.
Adding this flag caused issues with LLD, as it doesn't recognize it.
Rethinking the issue, using the undocumented flag seems like the incorrect solution: there's no guarantee that the flag won't be removed in the future, or change its meaning.
Instead, I've disabled the problematic test for Arm64 Windows and have filed a bug with the MSVC team to have the check removed: <https://developercommunity.microsoft.com/t/Remove-checking-for-and-fixing-Cortex-A/10905134>
This PR supersedes #140977
r? ```@jieyouxu```
Remove #![feature(let_chains)] from library and src/librustdoc
PR https://github.com/rust-lang/rust/pull/132833 has stabilized the `let_chains` feature. This PR removes the last occurences from the library, the compiler, and librustdoc (also because #140887 missed the conditional in one of the crates as it was behind the "rustc" feature).
We keep `core` as exercise for the future as updating it is non-trivial (see PR thread).
Add per page TOC in the `rustc` book
This PR adds per page Table of Content (TOC) in the `rustc` book (to be extended in the future to our other books).
The goal is to easy the navigation inside the page by providing quick overview of the page content and our position inside that page.
That functionality is unfortunately not available natively in `mdbook`, which prompted community members to create [mdBook-pagetoc](https://github.com/JorelAli/mdBook-pagetoc/) (which this PR is heavily inspired by). It's "only" a JS file (to handle the TOC) and a CSS file (to handle the margin, colors, screen size, ...), there is no "post-processor" needed (in mdbook sense).

Live preview at: http://urgau.rf.gd/book
r? ```@jieyouxu```
move expensive layout sanity check to debug assertions
It is [hard to fix](https://github.com/rust-lang/rust/issues/141006#issuecomment-2883415000) the slowness in the uninhabitedness computation for very big types but we can fix the very specific case of them being called during the layout sanity checks, as described in #140944.
So this PR moves this uninhabitedness check to the other expensive layout sanity checks that are ran under `debug_assertions`.
It makes building the `lemmy_api_routes` crate's self-profile `layout_of` query go from
```
+--------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| Item | Self time | % of total time | Time | Item count | Incremental result hashing time |
+--------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| layout_of | 63.02s | 41.895 | 244.26s | 123703 | 50.30ms |
+--------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
```
on master (2m17s total), to
```
| layout_of | 330.21ms | 0.372 | 26.90s | 123703 | 53.19ms |
```
with this PR (1m15s total).
(Note that the [perf run results](https://github.com/rust-lang/rust/pull/141039#issuecomment-2884688756) below look a bit better than [an earlier run](https://perf.rust-lang.org/compare.html?start=4eca99a18eab3d4e28ed1ce3ee620d442955a470&end=c4a00993f8ee02c7565e7be652608817ea2fb97d&stat=instructions:u) I did in another PR. There may be some positive noise there, or post-merge results could differ a bit)
Since we discussed this today, r? `@compiler-errors` — and cc `@lcnr` and `@RalfJung.`
Merge mir query analysis invocations
r? `@ghost`
same thing as https://github.com/rust-lang/rust/pull/140854 just a different set of queries
Doing this in general has some bad cache coherence issues because the query caches are laid out in Vec<QueryResult> lists per query where each index refers to a DefId in the same order as we're iterating. Iterating two or more lists at the same time does have cache issues, so I want to poke a bit at it to see if we can't merge just a few of them at a time.
Initial implementation of `core_float_math`
Since [1], `compiler-builtins` makes a certain set of math symbols
weakly available on all platforms. This means we can begin exposing some
of the related functions in `core`, so begin this process here.
It is not possible to provide inherent methods in both `core` and `std`
while giving them different stability gates, so standalone functions are
added instead. This provides a way to experiment with the functionality
while unstable; once it is time to stabilize, they can be converted to
inherent.
For `f16` and `f128`, everything is unstable so we can move the inherent
methods.
The following are included to start:
* floor
* ceil
* round
* round_ties_even
* trunc
* fract
* mul_add
* div_euclid
* rem_euclid
* powi
* sqrt
* abs_sub
* cbrt
These mirror the set of functions that we have in `compiler-builtins`
since [1], with the exception of `powi` that has been there longer.
Details for each of the changes is in the commit messages.
Tracking issue: https://github.com/rust-lang/rust/issues/137578
[1]: https://github.com/rust-lang/compiler-builtins/pull/763
try-job: aarch64-gnu
tru-job: armhf-gnu
try-job: i686-msvc-1
try-job: test-various
try-job: x86_64-mingw-1
try-job: x86_64-mingw-2
Rollup of 9 pull requests
Successful merges:
- #135808 (Implement Display for ``rustc_target::callconv::Conv``)
- #137432 (Add as_ascii_unchecked() methods to char, u8, and str)
- #139103 (deduplicate abort implementations)
- #140917 (checktools.sh: fix bashism)
- #141035 (turn lld warning on old gccs into info log)
- #141118 (Enable rust-analyzer to go from query definition to the corresponding provider field)
- #141121 (Only select true errors in `impossible_predicates`)
- #141125 (check coroutines with `TypingMode::Borrowck` to avoid cyclic reasoning)
- #141131 (Make some `match`es slightly more ergonomic in `librustdoc`)
r? `@ghost`
`@rustbot` modify labels: rollup
Make some `match`es slightly more ergonomic in `librustdoc`
Bunch of small cleanups I found while working on other stuff, mostly getting rid of superfluous `*`s and `ref [mut]`s in `match`es,
makes the code less sigil/keyword-heavy, and slightly improves readability IMHO.
Also flattens a few nested `match`es.
check coroutines with `TypingMode::Borrowck` to avoid cyclic reasoning
MIR borrowck taints its output if an obligation fails. This could then cause `check_coroutine_obligations` to silence its error, causing us to not emit and actual error and ICE.
Fixes the ICE in https://github.com/rust-lang/trait-system-refactor-initiative/issues/199. It is unfortunately still a regression.
r? compiler-errors
turn lld warning on old gccs into info log
As discussed in #140964 and IRL, this PR switches the spammy warning shown unconditionally when an old gcc doesn't support `-fuse-ld=lld` and we retry linking without it, to an info debug log so we don't lose it.
r? `@Mark-Simulacrum`
Fixes#140964
checktools.sh: fix bashism
Follow-up to https://github.com/rust-lang/rust/pull/140903. Turns out `tests/{pass,panic}` only properly expands in bash, not in dash. :/
r? `@WaffleLapkin`
deduplicate abort implementations
Currently, the code for process aborts is duplicated across `panic_abort` and `std`. This PR uses `#[rustc_std_internal_symbol]` to make the `std` implementation available to `panic_abort` via the linker, thereby deduplicating the code.
Add as_ascii_unchecked() methods to char, u8, and str
This PR adds the `as_ascii_unchecked()` method to `char`, `u8`, and `str`, allowing users to convert these types to `ascii::Char`s (see #110998) in an `unsafe` context without first checking for validity. This method was already available for `[u8]`, so this PR makes the API more consistent across other types.
MIR borrowck taints its output if an obligation fails. This could then cause
`check_coroutine_obligations` to silence its error, causing us to not emit
and actual error and ICE.
Rollup of 8 pull requests
Successful merges:
- #140208 (Make well-formedness predicates no longer coinductive)
- #140957 (Add `#[must_use]` to Array::map)
- #141031 (Async drop fix for dropee from another crate (#140858))
- #141036 (ci: split the dist-ohos job)
- #141051 (Remove some unnecessary erases)
- #141056 (Lowercase git url for rust-lang/enzyme.git)
- #141059 (HIR: explain in comment why `ExprKind::If` "then" is an `Expr`)
- #141070 (Do not emit help when shorthand from macro when suggest `?` or `expect`)
r? `@ghost`
`@rustbot` modify labels: rollup
Do not emit help when shorthand from macro when suggest `?` or `expect`
Fixes#140659
I didn't fully minimize the original bug, but I found a similar test case, and they have perhaps the same root cause. For the bug mentioned in #140659 , I also tested it locally and passed it.
Jieyou has worked on this part before, maybe r? `@jieyouxu`
HIR: explain in comment why `ExprKind::If` "then" is an `Expr`
One could be tempted to replace the "then" `hir::Expr` with kind `hir::ExprKind::Block` by a `hir::Block`. Explain why this would not be a good idea.
I've been there.
r? ``@compiler-errors``
Lowercase git url for rust-lang/enzyme.git
On Fuchsia, we have an internal Gerrit mirrors of the rust repositories to avoid excess load on the public github servers. Since rust uses submodules, we need to then use git's `url.<base>.insteadOf` to point our checkouts at our mirrors.
We'd prefer to be able to point all repositories under `https://github.com/rust-lang` to
`https://rust.googlesource.com/rust-lang`, but unfortunately it seems that when Rust mirrored Enzyme, the repository name was lower cased to `https://github.com/rust-lang/enzyme`, but kept the name capitalized in the .gitmodules file. This didn't cause a problem for Github, which seems to handle repository names in a case insensitive way, Gerrit is case sensitive, so we can't use a glob rule. Instead we have to setup `insteadOf` rules for each repository.
This renames the URL to match the case of the repository name, which should avoid the issue.
Async drop fix for dropee from another crate (#140858)
Fixes https://github.com/rust-lang/rust/issues/140858.
For `AsyncDestructor` impl def id was wrongly kept as a LocalDefId, which causes crash when dropee is declared in another crate.
Also, potential problem found:
when user crate drops type with async drop in dependency crate, and user crate doesn't enable `feature(async_drop)`, then sync drop version will be used.
Is it a problem? Do we need some notification about such situations?
Add `#[must_use]` to Array::map
The output of Array::map is intended to be an array of the same size, and does not modify the original in place nor is it intended for side-effects. Thus, under normal circumstances it should be consumed.
See [discussion](https://internals.rust-lang.org/t/array-map-annotate-with-must-use/22813/26).
Attaching to tracking issue #75243
Make well-formedness predicates no longer coinductive
This PR makes well-formedness no longer coinductive. It was made coinductive in https://github.com/rust-lang/rust/pull/98542, but AFAICT this was only to fix UI tests since we stopped lowering `where Ty:` to an empty-region outlives predicate but to a WF predicate instead.
Arguably it should lower to something completely different, something like a "type mentioned no-op predicate", but well-formedness serves this purpose fine today, and since no code (according to crater) relies on this coinductive behavior, we'd like to avoid having to emulate it in the new solver.
Fixes#123456 (I didn't want to add a test since it seems low-value to have a ICE test for a fuzzer minimization that is basically garbage code.)
Fixes#109764 (not sure if this behavior is emulatable w/o coinductive WF?)
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/169
r? lcnr
Revert "Fix linking statics on Arm64EC #140176"
This reverts PR #140176.
Unfortunately, this will reopen https://github.com/rust-lang/rust/issues/138541 (re-breaking the `arm64ec-pc-windows-msvc` target).
Unfortunately, multiple people are [reporting linker warnings related to `__rust_no_alloc_shim_is_unstable`](https://github.com/rust-lang/rust/pull/140176#issuecomment-2879715554) after this change in `x86_64-pc-windows-msvc` as well. The solution isn't quite clear yet, let's revert to avoid the linker warnings on the Tier 1 MSVC target for now[^timing], and try a reland with a determined solution for `__rust_no_alloc_shim_is_unstable`.
Judging from [people reporting that they are observing this also when bootstrapping w/ stage0 rustc](https://github.com/rust-lang/rust/pull/140176#issuecomment-2881867433), we may have to cut a new beta and then repoint stage0 against that newer beta?
cc `@dpaoliello` `@wesleywiser`
r? `@wesleywiser` (or compiler)
[^timing]: Note that it's still RustWeek this week, so most team members are N/A.
trait_sel: deep reject `match_normalize_trait_ref`
Spotted during an in-person review of #137944 at RustWeek: `match_normalize_trait_ref` could be using `DeepRejectCtxt` to exit early as an optimisation for projection candidates, like is done with param candidates.
r? `@lcnr`
cc `@oli-obk`