Always include a position span in `rustc_parse_format::Argument`
Moves the spans from the `Position` enum to always be included in the `Argument` struct. Doesn't make any changes to use it in rustc, but it will be useful for some upcoming Clippy lints
make `PlaceholderConst` not store the type of the const
Currently the `Placeholder` variant on `ConstKind` is 28 bytes when with this PR its 8 bytes, i am not sure this is really useful at all rn since `Unevaluated` and `Value` variants are huge still but eventually it should be possible to get both down to 16 bytes 🤔. Mostly opening this to see if this change has any perf impact when done before it can make `ConstKind`/`ConstS` smaller
`codegen_fulfill_obligation` expect erased regions
it's a query, so by erasing regions before calling it, we get better caching.
This doesn't actually change anything as its already the status quo.
Improve type mismatch w/ function signatures
This PR makes use of `note: expected/found` (instead of labeling types in labels) in type mismatch with function signatures. Pros: it's easier to compare the signatures, cons: the error is a little more verbose now.
This is especially nice when
- The signatures differ in a small subset of parameters (same parameters are elided)
- The difference is in details, for example `isize` vs `usize` (there is a better chance that the types align)
Also this PR fixes the inconsistency in variable names in the edited code (`expected` and `found`).
A zulip thread from which this pr started: [[link]](https://rust-lang.zulipchat.com/#narrow/stream/147480-t-compiler.2Fwg-diagnostics/topic/Type.20error.20regression.3F.2E.2E.2E/near/289756602).
An example diagnostic:
<table>
<tr>
<th>this pr</th>
<th>nightly</th>
</tr>
<tr>
<td>
```text
error[E0631]: type mismatch in function arguments
--> ./t.rs:4:12
|
4 | expect(&f);
| ------ ^^ expected due to this
| |
| required by a bound introduced by this call
...
10 | fn f(_: isize, _: u8, _: Vec<u32>) {}
| ---------------------------------- found signature defined here
|
= note: expected function signature `fn(usize, _, Vec<u64>) -> _`
found function signature `fn(isize, _, Vec<u32>) -> _`
note: required because of the requirements on the impl of `Trait` for `fn(isize, u8, Vec<u32>) {f}`
--> ./t.rs:8:9
|
8 | impl<F> Trait for F where F: Fn(usize, u8, Vec<u64>) -> u8 {}
| ^^^^^ ^
= note: required for the cast from `fn(isize, u8, Vec<u32>) {f}` to the object type `dyn Trait`
```
</td>
<td>
```text
error[E0631]: type mismatch in function arguments
--> ./t.rs:4:12
|
4 | expect(&f);
| ------ ^^ expected signature of `fn(usize, u8, Vec<u64>) -> _`
| |
| required by a bound introduced by this call
...
10 | fn f(_: isize, _: u8, _: Vec<u32>) {}
| ---------------------------------- found signature of `fn(isize, u8, Vec<u32>) -> _`
|
note: required because of the requirements on the impl of `Trait` for `fn(isize, u8, Vec<u32>) {f}`
--> ./t.rs:8:9
|
8 | impl<F> Trait for F where F: Fn(usize, u8, Vec<u64>) -> u8 {}
| ^^^^^ ^
= note: required for the cast to the object type `dyn Trait`
```
</td>
</tr>
</table>
<details><summary>code</summary>
<p>
```rust
fn main() {
fn expect(_: &dyn Trait) {}
expect(&f);
}
trait Trait {}
impl<F> Trait for F where F: Fn(usize, u8, Vec<u64>) -> u8 {}
fn f(_: isize, _: u8, _: Vec<u32>) {}
```
</p>
</details>
r? `@compiler-errors`
use `check_region_obligations_and_report_errors` to avoid ICEs
If we don't call `process_registered_region_obligations` before `resolve_regions_and_report_errors` then we'll ICE if we have any region obligations, and `check_region_obligations_and_report_errors` just does both of these for us in a nice convenient function.
Fixes#53475
r? types
Generate correct suggestion with named arguments used positionally
Address issue #99265 by checking each positionally used argument
to see if the argument is named and adding a lint to use the name
instead. This way, when named arguments are used positionally in a
different order than their argument order, the suggested lint is
correct.
For example:
```
println!("{b} {}", a=1, b=2);
```
This will now generate the suggestion:
```
println!("{b} {a}", a=1, b=2);
```
Additionally, this check now also correctly replaces or inserts
only where the positional argument is (or would be if implicit).
Also, width and precision are replaced with their argument names
when they exists.
Since the issues were so closely related, this fix for issue #99265
also fixes issue #99266.
Fixes#99265Fixes#99266
Deeply deny fn and raw ptrs in const generics
I think this is right -- just because we wrap a fn ptr in a wrapper type does not mean we should allow it in a const parameter.
We now reject both of these in the same way:
```
#![feature(adt_const_params)]
#[derive(Eq, PartialEq)]
struct Wrapper();
fn foo<const W: Wrapper>() {}
fn foo2<const F: fn()>() {}
```
This does regress one test (`src/test/ui/consts/refs_check_const_eq-issue-88384.stderr`), but I'm not sure it should've passed in the first place.
cc: ``@b-naber`` who introduced that test^
fixes#99641
Restore `Opaque` behavior to coherence check
Fixes#99663.
This broke in 84c3fcd2a0. I'm not exactly certain that adding this behavior back is necessarily correct, but at least the UI test I provided may stimulate some thoughts.
I think delaying a bug here is certainly not correct in the case of opaques -- if we want to change coherence behavior for opaques, then we should at least be emitting a new error.
r? ``@lcnr``
handle consts with param/infer in `const_eval_resolve` better
This PR addresses [this thread here](https://github.com/rust-lang/rust/pull/99449#discussion_r924141230). Was this the change you were looking for ``@lcnr?``
Interestingly, one test has begun to pass. Was that expected?
r? ``@lcnr``
Address issue #99265 by checking each positionally used argument
to see if the argument is named and adding a lint to use the name
instead. This way, when named arguments are used positionally in a
different order than their argument order, the suggested lint is
correct.
For example:
```
println!("{b} {}", a=1, b=2);
```
This will now generate the suggestion:
```
println!("{b} {a}", a=1, b=2);
```
Additionally, this check now also correctly replaces or inserts
only where the positional argument is (or would be if implicit).
Also, width and precision are replaced with their argument names
when they exists.
Since the issues were so closely related, this fix for issue #99265
also fixes issue #99266.
Fixes#99265Fixes#99266
Do not resolve associated const when there is no provided value
Fixes#98629, since now we just delay a bug when we're not able to evaluate a const item due to the value not actually being provided by anything. This means compilation proceeds forward to where the "missing item in impl" error is emitted.
----
The root issue here is that when we're looking for the defining `LeafDef` in `resolve_associated_item`, we end up getting the trait's AssocItem instead of the impl's AssocItem (which does not exist). This resolution "succeeds" even if the trait's item has no default value, and then since this item has no value to evaluate, it turns into a const eval error.
This root issue becomes problematic (as in #98629) when this const eval error happens in wfcheck (for example, due to normalizing the param-env of something that references this const). Since this happens sooner than the check that an impl actually provides all of the items that a trait requires (which happens during later typecheck), we end up aborting compilation early with only this un-informative message.
I'm not exactly sure _why_ this bug arises due to #96591 -- perhaps valtrees are evaluated more eagerly than in the old system?
r? ``@oli-obk`` or ``@lcnr`` since y'all are familiar with const eval and reviewed #96591, though feel free to reassign.
This is a regression from stable to beta, so I would be open to considering this for beta backport. It seems correct to me, especially given the improvements in the other UI tests this PR touches, but may have some side-effects that I'm unaware of...?
Fix hack that remaps env constness.
WARNING: might have perf implications.
Are there any more problems with having a constness in the `ParamEnv` now? :)
r? `@oli-obk`
Improve suggestions for returning binding
Fixes#99525
Also reworks the cause codes for match and if a bit, I think cleaning them up in a positive way.
We no longer need to call `could_remove_semicolon` in successful code, which might save a few cycles?
move `considering_regions` to the infcx
it seems weird to prove some obligations which constrain inference vars while ignoring regions in a context which considers regions. This is especially weird because even for a fulfillment context with ignored regions, we still added region outlives bounds when directly relating regions.
tbh our handling of regions is still very weird, but at least this is a step in the right direction imo.
r? rust-lang/types
