Still-further-specializable projections are ambiguous in new solver
Fixes https://github.com/rust-lang/rust/pull/108896/files#r1148450781
r? ``@BoxyUwU`` (though feel free to re-roll)
---
This can be used to create an unsound transmute function with the new solver:
```rust
#![feature(specialization)]
trait Default {
type Id;
fn intu(&self) -> &Self::Id;
}
impl<T> Default for T {
default type Id = T;
fn intu(&self) -> &Self::Id {
self
}
}
fn transmute<T: Default<Id = U>, U: Copy>(t: T) -> U {
*t.intu()
}
use std::num::NonZeroU8;
fn main() {
let s = transmute::<u8, Option<NonZeroU8>>(0);
assert_eq!(s, None);
}
```
Improve "Auto-hide trait implementation documentation" GUI test
Part of #66181.
I'll start working on the `include` command for `browser-ui-test` so we can greatly reduce the duplicated code between setting tests.
r? ``@notriddle``
Permit the MIR inliner to inline diverging functions
This heuristic prevents inlining of `hint::unreachable_unchecked`, which in turn makes `Option/Result::unwrap_unchecked` a bad inlining candidate. I looked through the changes to `core`, `alloc`, `std`, and `hashbrown` by hand and they all seem reasonable. Let's see how this looks in perf...
---
Based on rustc-perf it looks like this regresses ctfe-stress, and the cachegrind diff indicates that this regression is in `InterpCx::statement`. I don't know how to do any deeper analysis because that function is _enormous_ in the try toolchain, which has no debuginfo in it. And a local build produces significantly different codegen for that function, even with LTO.
Upgrade to LLVM 16, again
Relative to the previous attempt in https://github.com/rust-lang/rust/pull/107224:
* Update to GCC 8.5 on dist-x86_64-linux, to avoid std::optional ABI-incompatibility between libstdc++ 7 and 8.
* Cherry-pick 96df79af02.
* Cherry-pick 6fc670e5e3.
r? `@cuviper`
Use poison instead of undef
In cases where it is legal, we should prefer poison values over undef values.
This replaces undef with poison for aggregate construction and for uninhabited types. There are more places where we can likely use poison, but I wanted to stay conservative to start with.
In particular the aggregate case is important for newer LLVM versions, which are not able to handle an undef base value during early optimization due to poison-propagation concerns.
r? `@cuviper`
Implement non-const `Destruct` trait in new solver
Makes it so that we can call stdlib methods like `Option::map` in **non-const** environments, since *many* stdlib methods have `Destruct` bounds 😅
This doesn't bother to implement `const Destruct` yet, but it shouldn't be too hard to do so. Just didn't bother since we already don't have much support for const traits in the new solver anyways. I'd be happy to add skeleton support for `const Destruct`, though, if the reviewer desires.
Return nested obligations from canonical response var unification
Handle alias-eq obligations being emitted from `instantiate_and_apply_query_response` in:
* `EvalCtxt` - by processing the nested obligations in the next loop by `new_goals`
* `FulfillCtxt` - by adding the nested obligations to the fulfillment's pending obligations
* `InferCtxt::evaluate_obligation` - ~~by returning `EvaluationResult::EvaluatedToAmbig` (boo 👎, see the FIXME)~~ same behavior as above, since we use fulfillment and `select_where_possible`
The only one that's truly sketchy is `evaluate_obligation`, but it's not hard to modify this behavior moving forward.
From #109037, I think a smaller repro could be crafted if I were smarter, but I am not, so I just took this from #105878.
r? `@lcnr` cc `@BoxyUwU`
sync LVI tests
The LVI tests for the `x86_64-fortanix-unknown-sgx` target have gotten out of sync. LVI is still mitigated correctly, but the LVI tests need minor modifications. Other (non LVI-related) tests fail when the target applies LVI mitigations as they assume the generated code contains forbidden instructions such as `retq`. These tests are ignored for the sgx environment.
cc: `@jethrogb`
Refine error spans for const args in hir typeck
Improve just a couple of error messages having to do with mismatched consts.
r? `@ghost` i'll put this up when the dependent commits are merged
rustdoc: add support for type filters in arguments and generics
This makes sense, since the search index has the information in it, and it's more useful for function signature searches since a function signature search's item type is, by definition, some type of function (there's more than one, but not very many).
Move useless_anynous_reexport lint into unused_imports
As mentioned in https://github.com/rust-lang/rust/pull/109003, this check should have been merged with `unused_imports` in the start.
r? `@petrochenkov`
Lint ambiguous glob re-exports
Attempts to fix#107563.
We currently already emit errors for ambiguous re-exports when two names are re-exported *specifically*, i.e. not from glob exports. This PR attempts to emit deny-by-default lints for ambiguous glob re-exports.
Add `-Z time-passes-format` to allow specifying a JSON output for `-Z time-passes`
This adds back the `-Z time` option as that is useful for [my rustc benchmark tool](https://github.com/Zoxc/rcb), reverting https://github.com/rust-lang/rust/pull/102725. It now uses nanoseconds and bytes as the units so it is renamed to `time-precise`.
rustc_interface: Add a new query `pre_configure`
It partially expands crate attributes before the main expansion pass (without modifying the crate), and the produced preliminary crate attribute list is used for querying a few attributes that are required very early.
Crate-level cfg attributes on the crate itself are then expanded normally during the main expansion pass, like attributes on any other nodes.
This is a continuation of https://github.com/rust-lang/rust/pull/92473 and one more step to very unstable crate-level proc macro attributes maybe actually working.
Previously crate attributes were pre-configured simultaneously with feature extraction, and then written directly into `ast::Crate`.
Rollup of 7 pull requests
Successful merges:
- #108541 (Suppress `opaque_hidden_inferred_bound` for nested RPITs)
- #109137 (resolve: Querify most cstore access methods (subset 2))
- #109380 (add `known-bug` test for unsoundness issue)
- #109462 (Make alias-eq have a relation direction (and rename it to alias-relate))
- #109475 (Simpler checked shifts in MIR building)
- #109504 (Stabilize `arc_into_inner` and `rc_into_inner`.)
- #109506 (make param bound vars visibly bound vars with -Zverbose)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
