Expect that equating a projection term always succeeds in new solver
These should never fail. If they do, we have a problem with the logic that replaces a projection goal's term with an unconstrained infer var. Let's make sure we ICE in that case.
Clone region var origins instead of taking them in borrowck
Fixes an issue with the new solver where reporting a borrow-checker error ICEs because it calls `InferCtxt::evaluate_obligation`.
This also removes a handful of unnecessary `tcx.infer_ctxt().build()` calls that are only there to mitigate this same exact issue, but with the old solver.
Fixescompiler-errors/next-solver-hir-issues#12.
----
This implements `@aliemjay's` solution where we just don't *take* the region constraints, but clone them. This potentially makes it easier to write a bug about taking region constraints twice or never at all, but again, not many folks are touching this code.
Report allocation errors as panics
OOM is now reported as a panic but with a custom payload type (`AllocErrorPanicPayload`) which holds the layout that was passed to `handle_alloc_error`.
This should be review one commit at a time:
- The first commit adds `AllocErrorPanicPayload` and changes allocation errors to always be reported as panics.
- The second commit removes `#[alloc_error_handler]` and the `alloc_error_hook` API.
ACP: https://github.com/rust-lang/libs-team/issues/192Closes#51540Closes#51245
Evaluate place expression in `PlaceMention`
https://github.com/rust-lang/rust/pull/102256 introduces a `PlaceMention(place)` MIR statement which keep trace of `let _ = place` statements from surface rust, but without semantics.
This PR proposes to change the behaviour of `let _ =` patterns with respect to the borrow-checker to verify that the bound place is live.
Specifically, consider this code:
```rust
let _ = {
let a = 5;
&a
};
```
This passes borrowck without error on stable. Meanwhile, replacing `_` by `_: _` or `_p` errors with "error[E0597]: `a` does not live long enough", [see playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=c448d25a7c205dc95a0967fe96bccce8).
This PR *does not* change how `_` patterns behave with respect to initializedness: it remains ok to bind a moved-from place to `_`.
The relevant test is `tests/ui/borrowck/let_underscore_temporary.rs`. Crater check found no regression.
For consistency, this PR changes miri to evaluate the place found in `PlaceMention`, and report eventual dangling pointers found within it.
r? `@RalfJung`
Remove some uses of dynamic dispatch during monomorphization/partitioning.
This removes a few uses of dynamic dispatch and instead uses generics, as well as an enum to allow for other partitioning methods to be added later.
Print ty placeholders pretty
Makes anon placeholders print like `!0` instead of `Placeholder { ... }`.
```
rustc_trait_selection::solve::compute_well_formed_goal goal=Goal{
predicate: !0,
param_env: ParamEnv{
caller_bounds: [
Binder(TraitPredicate(<!0 as std::marker::Copy>, polarity: Positive), []),
Binder(TraitPredicate(<!0 as std::clone::Clone>, polarity: Positive), []),
Binder(TraitPredicate(<!0 as std::marker::Sized>, polarity: Positive), []),
],
reveal: UserFacing,
constness: NotConst,
}
}
```
cc `@BoxyUwU` who might care about this formatting decision
Stable hash tag (discriminant) of `GenericArg`
This is a continuation of my quest of removing `transmute` if generic args and types (#110496, #110599).
r? `@compiler-errors`
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
Rollup of 5 pull requests
Successful merges:
- #110333 (rustc_metadata: Split `children` into multiple tables)
- #110501 (rustdoc: fix ICE from rustc_resolve and librustdoc parse divergence)
- #110608 (Specialize some `io::Read` and `io::Write` methods for `VecDeque<u8>` and `&[u8]`)
- #110632 (Panic instead of truncating if the incremental on-disk cache is too big)
- #110633 (More `mem::take` in `library`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Ensure mir_drops_elaborated_and_const_checked when requiring codegen.
mir_drops_elaborated_and_const_checked may emit errors while codegen has started, and the compiler would exit leaving object code files around.
Found by `@cuviper` in https://github.com/rust-lang/rust/issues/109731
Deduplicate unreachable blocks, for real this time
In https://github.com/rust-lang/rust/pull/106428 (in particular 41eda69516) we noticed that inlining `unreachable_unchecked` can produce duplicate unreachable blocks. So we improved two MIR optimizations: `SimplifyCfg` was given a simplify to deduplicate unreachable blocks, then `InstCombine` was given a combiner to deduplicate switch targets that point at the same block. The problem is that change doesn't actually work.
Our current pass order is
```
SimplifyCfg (does nothing relevant to this situation)
Inline (produces multiple unreachable blocks)
InstCombine (doesn't do anything here, oops)
SimplifyCfg (produces the duplicate SwitchTargets that InstCombine is looking for)
```
So in here, I have factored out the specific function from `InstCombine` and placed it inside the simplify that produces the case it is looking for. This should ensure that it runs in the scenario it was designed for.
Fixes https://github.com/rust-lang/rust/issues/110551
r? `@cjgillot`
Panic instead of truncating if the incremental on-disk cache is too big
It seems _unlikely_ that anyone would hit this truncation, but if this `as` does actually truncate, that seems incredibly bad.
rustc_metadata: Split `children` into multiple tables
instead of merging everything into a single bag.
If it's acceptable from performance point of view, then it's more clear to keep this stuff organized more in accordance with its use.
instead of merging everything into a single bag.
If it's acceptable from performance point of view, then it's more clear to keep this stuff organized more in accordance with its use.
Added byte position range for `proc_macro::Span`
Currently, the [`Debug`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#impl-Debug-for-Span) implementation for [`proc_macro::Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) calls the debug function implemented in the trait implementation of `server::Span` for the type `Rustc` in the `rustc-expand` crate.
The current implementation, of the referenced function, looks something like this:
```rust
fn debug(&mut self, span: Self::Span) -> String {
if self.ecx.ecfg.span_debug {
format!("{:?}", span)
} else {
format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
}
}
```
It returns the byte position of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) as an interpolated string.
Because this is currently the only way to get a spans position in the file, I might lead someone, who is interested in this information, to parsing this interpolated string back into a range of bytes, which I think is a very non-rusty way.
The proposed `position()`, method implemented in this PR, gives the ability to directly get this info.
It returns a [`std::ops::Range`](https://doc.rust-lang.org/std/ops/struct.Range.html#) wrapping the lowest and highest byte of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#).
I put it behind the `proc_macro_span` feature flag because many of the other functions that have a similar footprint also are annotated with it, I don't actually know if this is right.
It would be great if somebody could take a look at this, thank you very much in advanced.
