Don't try to label `ObligationCauseCode::CompareImplItem` for an RPITIT, since it has no name
The old (current) trait solver has a limitation that when a where clause in param-env must be normalized using the same where clause, then we get spurious errors in `normalize_param_env_or_error`. I don't think there's an issue tracking it, but it's the root cause for many of the "fixed-by-next-solver" labeled issues.
Specifically, these errors may occur when checking predicate entailment of the GAT that comes out of desugaring RPITITs. Since we use `ObligationCauseCode::CompareImplItem` for these predicates, we try calling `item_name` on an RPITIT which fails, since the RPITIT has no name.
We simply suppress this logic when we're reporting a predicate entailment error for an RPITIT. RPITITs should never have predicate entailment errors, *by construction*, but they may due to this bug in the old solver.
Addresses the ICE in #127331, though doesn't fix the underlying issue (which is fundamental to the old solver).
r? types
Uplift outlives components to `rustc_type_ir`
We need this to uplift `push_outlives_components`, since the elaborator uses `push_outlives_components` to elaborate type outlives obligations and I want to uplift elaboration.
This ends up reworking and inlining a fair portion of the `GenericArg::walk_shallow` function, whose only callsite was this one. I believe I got the logic correct, but may be worthwhile to look at it closely just in case. Unfortunately github was too dumb to understand that this is a rename + change -- I could also rework the git history to split the "copy the file over" part from the actual logical changes if that makes this easier to review.
r? lcnr
Elaboration tweaks
Removes `Filter::OnlySelfThatDefines` and reimplements `transitive_bounds_that_define_assoc_item` as a separate function, since I don't want to have to uplift that mode since it's both an implementation detail (only exists to avoid cycles in astconv) and requires exposing `Ident` as an associated type on `Interner`.
r? lcnr
offset_from, offset: clearly separate safety requirements the user needs to prove from corollaries that automatically follow
By landing https://github.com/rust-lang/rust/pull/116675 we decided that objects larger than `isize::MAX` cannot exist in the address space of a Rust program, which lets us simplify these rules.
For `offset_from`, we can even state that the *absolute* distance fits into an `isize`, and therefore exclude `isize::MIN`. This PR also changes Miri to treat an `isize::MIN` difference like the other isize-overflowing cases.
Match ergonomics 2024: align with RFC again
- `&` matches `&mut` on old editions
- Add some more tests
r? ``@Nadrieril``
cc https://github.com/rust-lang/rust/issues/123076
``@rustbot`` label A-edition-2024 A-patterns
Added dots at the sentence ends of rustc AST doc
Just a tiny improvement for the AST documentation by bringing consistency to sentence ends. I intentionally didn't terminate every sentence, there are still some members not having them, but at least there's no mixing style on the type level.
Use `ControlFlow` results for visitors that are only looking for a single value
These visitors all had a `Option<Value>` or `bool` field, that, once set, was never unset or modified again. They have been refactored by removing the field and returning `ControlFlow` directly from the visitor
Split `SolverDelegate` back out from `InferCtxtLike`
This is because in order to uplift things like the `Generalizer` and other `TypeRelation`s, we want to be able to interface with `InferCtxtLike` (and `InferCtxt` as its implementation), rather that `SolverDelegate`, which only really exists as a hack to be able to define some downstream methods in `rustc_type_ir`.
r? lcnr
Improve well known value check-cfg diagnostic for the standard library
This PR adjust the current logic for hidding the rustc/Cargo suggestion to add a value to a well-known name to exclude the standard library and rustc crates.
This is done in order to improve the contributor experience, in particular when adding a new target, which often requires adding some cfgs like `target_os` which may not be available yet in stage0.
<details>
The diagnostic code would look like this.
```text
error: unexpected `cfg` condition value: `blable`
--> library/core/src/lib.rs:369:7
|
369 | #[cfg(target_os = "blable")]
| ^^^^^^^^^^^^^^^^^^^^
|
= note: expected values for `target_os` are: `aix`, `android`, `cuda`, `dragonfly`, `emscripten`, `espidf`, `freebsd`, `fuchsia`, `haiku`, `hermit`, `horizon`, `hurd`, `illumos`, `ios`, `l4re`, `linux`, `macos`, `netbsd`, `none`, `nto`, `openbsd`, `psp`, `redox`, `solaris`, `solid_asp3`, `teeos`, `tvos`, `uefi`, `unknown`, `visionos`, `vita`, `vxworks`, `wasi`, `watchos`, and `windows` and 2 more
= help: consider using a Cargo feature instead
= help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[lints.rust]
unexpected_cfgs = { level = "warn", check-cfg = ['cfg(target_os, values("blable"))'] }
= help: or consider adding `println!("cargo::rustc-check-cfg=cfg(target_os, values(\"blable\"))");` to the top of the `build.rs`
= note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
= note: `-D unexpected-cfgs` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(unexpected_cfgs)]`
```
</details>
Improve dead code analysis
Fixes#120770
1. check impl items later if self ty is private although the trait method is public, cause we must use the ty firstly if it's private
2. mark the adt live if it appears in pattern, like generic argument, this implies the use of the adt
3. based on the above, we can handle the case that private adts impl Default, so that we don't need adding rustc_trivial_field_reads on Default, and the logic in should_ignore_item
r? ``@pnkfelix``
coverage: Rename `mir::coverage::BranchInfo` to `CoverageInfoHi`
This opens the door to collecting and storing coverage information that is unrelated to branch coverage or MC/DC, during MIR building.
There is no change to the output of coverage instrumentation, but one deliberate change is that functions now *always* have an attached `CoverageInfoHi` (if coverage is enabled and they are eligible), even if they didn't collect any interesting branch information.
---
`@rustbot` label +A-code-coverage
DependencyList: removed outdated comment
Comment was outdated. Didn't updated description, as `Linkage` enum have descriptive names.
Also added fixme about moving this file to rustc_metadata.
Match ergonomics 2024: Implement TC's match ergonomics proposal
Under gate `ref_pat_eat_one_layer_2024_structural`. Enabling `ref_pat_eat_one_layer_2024` at the same time allows the union of what the individual gates allow. `@traviscross`
r? `@Nadrieril`
cc https://github.com/rust-lang/rust/issues/123076
`@rustbot` label A-edition-2024 A-patterns
Miri function identity hack: account for possible inlining
Having a non-lifetime generic is not the only reason a function can be duplicated. Another possibility is that the function may be eligible for cross-crate inlining. So also take into account the inlining attribute in this Miri hack for function pointer identity.
That said, `cross_crate_inlinable` will still sometimes return true even for `inline(never)` functions:
- when they are `DefKind::Ctor(..) | DefKind::Closure` -- I assume those cannot be `InlineAttr::Never` anyway?
- when `cross_crate_inline_threshold == InliningThreshold::Always`
so maybe this is still not quite the right criterion to use for function pointer identity.
cache type sizes in type-size limit visitor
This is basically https://github.com/rust-lang/rust/pull/125507#issuecomment-2206813779 as lcnr can't open the PR now.
Locally it reduces the `itertools` regression by quite a bit, to "only +50%" compared to nightly (that includes overhead from the local lack of artifact post-processing, and is just a data point to compare to the 10-20x timings without the cache).
```console
Benchmark 1: cargo +stage1 build --release
Time (mean ± σ): 2.721 s ± 0.009 s [User: 2.446 s, System: 0.325 s]
Range (min … max): 2.710 s … 2.738 s 10 runs
Benchmark 2: cargo +nightly build --release
Time (mean ± σ): 1.784 s ± 0.005 s [User: 1.540 s, System: 0.279 s]
Range (min … max): 1.778 s … 1.792 s 10 runs
Summary
cargo +nightly build --release ran
1.52 ± 0.01 times faster than cargo +stage1 build --release
```
On master, it's from 34s to the 2.7s above.
r? compiler-errors
