Download, rather than sccache-cache, LLVM in CI
My hope/expectation is that we can do better than sccache in CI for cached builds -- currently it looks like on macOS those still take upwards of 10-11 minutes, which is a significant amount of time that we could potentially cut.
This enables this mode for all non-dist builders; this should avoid any problems with the artifacts we distribute, while also providing for faster test builders (since they'll make use of PGO'd LLVM on the platforms we do that on, which is hopefully a nice win). It slightly increases the chance of test builders starting to fail only after a PR is merged (if PGO changes runtime behavior), but that should hopefully never happen, so I think this is worthwhile.
Measurements on the PR for apple-1 don't show any noticeable improvement in CI times, but those can be pretty noisy -- I'm inclined to land this since it *should* pretty much always be better and we can reconsider if that ever turns out not to be the case.
Refactor: remove unnecessary string searchings
This patch removes unnecessary string searchings for checking if function arguments have `&` and `&mut`.
Reenable disabled early syntax gates as future-incompatibility lints
- MCP: https://github.com/rust-lang/compiler-team/issues/535
The approach taken by this PR is
- Introduce a new lint, `unstable_syntax_pre_expansion`, and reenable the early syntax gates to emit it
- Use the diagnostic stashing mechanism to stash warnings the early warnings
- When the hard error occurs post expansion, steal and cancel the early warning
- Don't display any stashed warnings if errors are present to avoid the same noise problem that hiding type ascription errors is avoiding
Commits are working commits, but in a coherent steps-to-implement manner. Can be squashed if desired.
The preexisting `soft_unstable` lint seems like it would've been a good fit, but it is deny-by-default (appropriate for `#[bench]`) and these gates should be introduced as warn-by-default.
It may be desirable to change the stash mechanism's behavior to not flush lint errors in the presence of other errors either (like is done for warnings here), but upgrading a stash-using lint from warn to error perhaps is enough of a request to see the lint that they shouldn't be hidden; additionally, fixing the last error to get new errors thrown at you always feels bad, so if we know the lint errors are present, we should show them.
Using a new flag/mechanism for a "weak diagnostic" which is suppressed by other errors may also be desirable over assuming any stashed warnings are "weak," but this is the first user of stashing warnings and seems an appropriate use of stashing (it follows the "know more later to refine the diagnostic" pattern; here we learn that it's in a compiled position) so we get to define what it means to stash a non-hard-error diagnostic.
cc `````@petrochenkov````` (seconded MCP)
Add LLVM15-specific codegen test for `try`/`?`s that now optimize away
These still generated a bunch of code back in Rust 1.63 (<https://rust.godbolt.org/z/z31P8h6rz>), but with LLVM 15 merged they no longer do 🎉
Make `same_type_modulo_infer` a proper `TypeRelation`
Specifically, this fixes#100690 because we no longer consider a `ReLateBound` and a `ReVar` to be equal. `ReVar` can only be equal to free regions or static.
Initial implementation of REUSE
This PR implements the first two steps of #99414 by:
* Adding some scaffolding for REUSE. The `.reuse/dep5` file now marks every file as the custom "TODO" license, which I'll remove in a future PR once Debian imports their metadata. The TODO license is needed so that `reuse lint` works.
* Runs `reuse lint` in CI, in the `mingw-check` builder. REUSE currently has a bug when parsing some files in the LLVM source code. This means REUSE will fail when running it in source tarballs of rustc, and that bug prevents us from passing the `--include-submodules` flag in CI. I opened https://github.com/fsfe/reuse-tool/pull/560 upstream with a fix, and as soon as it's merged/released I planned to bump the pinned version to include the fix we need.
r? `@Mark-Simulacrum`
See comment added for details on the test builder restriction. This is primarily
intended for macOS CI, but is likely to be a slight win on other builders too.
suggest `once_cell::Lazy` for non-const statics
Addresses https://github.com/rust-lang/rust/issues/100410
Some questions:
- removing the `if` seems to include too many cases (e.g. calls to non-const functions inside a `const fn`), but this code excludes the following case:
```rust
const FOO: Foo = non_const_fn();
```
Should we suggest `once_cell` in this case as well?
- The original issue mentions suggesting `AtomicI32` instead of `Mutex<i32>`, should this PR address that as well?
Mention `as_mut` alongside `as_ref` in borrowck error message
Kinda fixes#99426 but I guess that really might be better staying open to see if we could make it suggest `as_mut` in a structured way. Not sure how to change borrowck to know that info tho.
Rollup of 9 pull requests
Successful merges:
- #99576 (Do not allow `Drop` impl on foreign fundamental types)
- #100081 (never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn))
- #100208 (make NOP dyn casts not require anything about the vtable)
- #100494 (Cleanup rustdoc themes)
- #100522 (Only check the `DefId` for the recursion check in MIR inliner.)
- #100592 (Manually implement Debug for ImportKind.)
- #100598 (Don't fix builtin index when Where clause is found)
- #100721 (Add diagnostics lints to `rustc_type_ir` module)
- #100731 (rustdoc: count deref and non-deref as same set of used methods)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Lazily decode SourceFile from metadata
Currently, source files from foreign crates are decoded up-front from metadata.
Spans from those crates were matched with the corresponding source using binary search among those files.
This PR changes the strategy by matching spans to files during encoding. This allows to decode source files on-demand, instead of up-front. The on-disk format for spans becomes: `<tag> <position from start of file> <length> <file index> <crate (if foreign file)>`.
This verifies if the HEAD sha matches with the detected LLVM SHA, and if not,
permits usage of the detected LLVM. Otherwise, we fallback on regular
non-downloaded LLVM (currently still cached with sccache, though that's still
10+ minutes on macOS).
Don't fix builtin index when Where clause is found
Where clause shadows blanket impl for `Index` which causes normalization to not occur, which causes ICE to happen when we typeck.
r? `@compiler-errors`
Fixes#91633
Cleanup rustdoc themes
This PR continues our work to simplify the rustdoc themes by relying more on CSS variables. Interestingly enough, this time it allowed me to realize that we were having a lot of different colors for borders even though the difference is unnoticeable. I used this opportunity to unify them.
The live demo is [here](https://rustdoc.crud.net/imperio/cleanup-themes/std/index.html).
r? `@jsha`
never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn)
Judging from https://github.com/rust-lang/rust/issues/71668#issuecomment-1200317370 the consensus nowadays seems to be that we should never consider an unsafe block unused if it was required with `deny(unsafe_op_in_unsafe_fn)`, no matter whether that lint is actually enabled or not. So let's adjust rustc accordingly.
The first commit does the change, the 2nd does some cleanup.
Do not allow `Drop` impl on foreign fundamental types
`Drop` should not be implemented on `Pin<T>` even if `T` is local.
This does not trigger regular orphan rules is because `Pin` is `#[fundamental]`... but we don't allow specialized `Drop` impls anyways, so these rules are not sufficient to prevent this impl on stable. Let's just choose even stricter rules, since we shouldn't be implementing `Drop` on a foreign ADT ever.
Fixes#99575
Revert "Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, …
…r=oli-obk"
This reverts commit c703d11dcc, reversing
changes made to 64eb9ab869.
it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).
r? `@pnkfelix`
fixes#99536
