```
error: `size_of_val` is not yet stable as a const intrinsic
--> $DIR/const-unstable-intrinsic.rs:17:9
|
LL | unstable_intrinsic::size_of_val(&x);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: add `#![feature(unstable)]` to the crate attributes to enable
help: add `#![feature(unstable)]` to the crate attributes to enable
|
LL + #![feature("unstable")]
|
```
const traits: remove some known-bug that do not seem to make sense
These tests were made to point to #103507 in https://github.com/rust-lang/rust/pull/114134; I think that was a mistake: that issue is about a rather specific problem, and most tests marked as known-bug in that PR are pointing at https://github.com/rust-lang/rust/issues/110395 which makes more sense.
Of the 4 tests that still point to #103507:
- One is [the original test](2088260852/tests/ui/impl-trait/normalize-tait-in-const.rs). It still fails to compile, though currently for unrelated reasons (`~const Fn` is not valid as that is not a const trait). I made it point at #110395 like all the other tests that were disabled when the previous const trait impl was removed.
- One is being fixed in https://github.com/rust-lang/rust/pull/135423
- The other two are fixed in this PR
The errors we are getting here are not great but they do look correct?
FWIW there are still a whole lot of tests mentioning #110395 despite that issue being closed... I hope someone is tracking that.^^
r? `@compiler-errors`
Rollup of 7 pull requests
Successful merges:
- #132397 (Make missing_abi lint warn-by-default.)
- #133807 (ci: Enable opt-dist for dist-aarch64-linux builds)
- #134143 (Convert `struct FromBytesWithNulError` into enum)
- #134338 (Use a C-safe return type for `__rust_[ui]128_*` overflowing intrinsics)
- #134678 (Update `ReadDir::next` in `std::sys::pal::unix::fs` to use `&raw const (*p).field` instead of `p.byte_offset().cast()`)
- #135424 (Detect unstable lint docs that dont enable their feature)
- #135520 (Make sure we actually use the right trivial lifetime substs when eagerly monomorphizing drop for ADTs)
r? `@ghost`
`@rustbot` modify labels: rollup
Depth limit const eval query
Currently the const-eval query doesn't have a recursion limit or timeout, causing the complier to freeze in an infinite loop, see #125718. This PR depth limits the `eval_to_const_value_raw` query (with the [`recursion_limit`](https://doc.rust-lang.org/reference/attributes/limits.html) attribute) and improves the diagnostics for query overflow errors, so spans are reported for other dep kinds than `layout_of` (e.g. `eval_to_const_value_raw`).
fixes#125718fixes#114192
When we encounter a constant in a pattern, we check if it is non-structural. If so, we check if the type implements `PartialEq`, but for types with escaping bound vars the check would be incorrect as is, so we break early. This is ok because these types would be filtered anyways.
Fix#134764.
rustc_intrinsic: support functions without body
We synthesize a HIR body `loop {}` but such bodyless intrinsics.
Most of the diff is due to turning `ItemKind::Fn` into a brace (named-field) enum variant, because it carries a `bool`-typed field now. This is to remember whether the function has a body. MIR building panics to avoid ever translating the fake `loop {}` body, and the intrinsic logic uses the lack of a body to implicitly mark that intrinsic as must-be-overridden.
I first tried actually having no body rather than generating the fake body, but there's a *lot* of code that assumes that all function items have HIR and MIR, so this didn't work very well. Then I noticed that even `rustc_intrinsic_must_be_overridden` intrinsics have MIR generated (they are filled with an `Unreachable` terminator) so I guess I am not the first to discover this. ;)
r? `@oli-obk`
Improve infer (`_`) suggestions in `const`s and `static`s
Fixes https://github.com/rust-lang/rust/issues/135010.
This PR does a few things to (imo) greatly improve the error message when users write something like `static FOO: [i32; _] = [1, 2, 3]`.
Firstly, it adapts the recovery code for when we encounter `_` in a const/static to work a bit more like `fn foo() -> _`, and removes the somewhat redundant query `diagnostic_only_typeck`.
Secondly, it changes the lowering for `[T; _]` to always lower under the `feature(generic_arg_infer)` logic to `ConstArgKind::Infer`. We still issue the feature error, so it's not doing anything *observable* on the good path, but it does mean that we no longer erroneously interpret `[T; _]`'s array length as a `_` **wildcard expression** (à la destructuring assignment, like `(_, y) = expr`).
Lastly it makes the suggestions verbose and fixes (well, suppresses) a bug with stashing and suggestions.
r? oli-obk
stabilize const_swap
libs-api FCP passed in https://github.com/rust-lang/rust/issues/83163.
However, I only just realized that this actually involves an intrinsic. The intrinsic could be implemented entirely with existing stable const functionality, but we choose to make it a primitive to be able to detect more UB. So nominating for `@rust-lang/lang` to make sure they are aware; I leave it up to them whether they want to FCP this.
While at it I also renamed the intrinsic to make the "nonoverlapping" constraint more clear.
Fixes#83163
Make `ty::Error` implement all auto traits
I have no idea what's up with the crashes test I fixed--I really don't want to look into it since it has to do something with borrowck and multiple layers of opaques. I think the underlying idea of allowing error types to implement all auto traits is justified though.
Fixes#134796Fixes#131050
r? lcnr
Correctly note item kind in `NonConstFunctionCall` error message
Don't just call everything a "`fn`". This is more consistent with the error message we give for conditionally-const items, which do note the item's def kind.
r? fmease, this is a prerequisite for making those `~const PartialEq` error messages better. Re-roll if you're busy or don't want to review this.
Bounds-check with PtrMetadata instead of Len in MIR
Rather than emitting `Len(*_n)` in array index bounds checks, emit `PtrMetadata(copy _n)` instead -- with some asterisks for arrays and `&mut` that need it to be done slightly differently.
We're getting pretty close to removing `Len` entirely, actually. I think just one more PR after this (for slice drop shims).
r? mir
Consider comments and bare delimiters the same as an "empty line" for purposes of hiding rendered code output of long multispans. This results in more aggressive shortening of rendered output without losing too much context, specially in `*.stderr` tests that have "hidden" comments.
fix ICE on type error in promoted
Fixes https://github.com/rust-lang/rust/issues/133968
Ensure that when we turn a type error into a "this promoted failed to evaluate" error, we do record this as something that may happen even in "infallible" promoteds.
Add context to "const in pattern" errors
*Each commit addresses specific diagnostics.*
- Add primary span labels
- Point at `const` item, and `const` generic param definition
- Reword messages and notes
- Point at generic param through which an associated `const` is being referenced
- Silence const in pattern with evaluation errors when they come from `const` items that already emit a diagnostic
- On non-structural type in const used as pattern, point at the type that should derive `PartialEq`
Add lint against function pointer comparisons
This is kind of a follow-up to https://github.com/rust-lang/rust/pull/117758 where we added a lint against wide pointer comparisons for being ambiguous and unreliable; well function pointer comparisons are also unreliable. We should IMO follow a similar logic and warn people about it.
-----
## `unpredictable_function_pointer_comparisons`
*warn-by-default*
The `unpredictable_function_pointer_comparisons` lint checks comparison of function pointer as the operands.
### Example
```rust
fn foo() {}
let a = foo as fn();
let _ = a == foo;
```
### Explanation
Function pointers comparisons do not produce meaningful result since they are never guaranteed to be unique and could vary between different code generation units. Furthermore different function could have the same address after being merged together.
----
This PR also uplift the very similar `clippy::fn_address_comparisons` lint, which only linted on if one of the operand was an `ty::FnDef` while this PR lints proposes to lint on all `ty::FnPtr` and `ty::FnDef`.
```@rustbot``` labels +I-lang-nominated
~~Edit: Blocked on https://github.com/rust-lang/libs-team/issues/323 being accepted and it's follow-up pr~~
Point at types that need to be marked with `#[derive(PartialEq)]`.
We use a visitor to look at a type that isn't structural, looking for all ADTs that don't derive `PartialEq`. These can either be manual `impl PartialEq`s or no `impl` at all, so we differentiate between those two cases to provide more context to the user. We also only point at types and impls from the local crate, otherwise show only a note.
```
error: constant of non-structural type `&[B]` in a pattern
--> $DIR/issue-61188-match-slice-forbidden-without-eq.rs:15:9
|
LL | struct B(i32);
| -------- must be annotated with `#[derive(PartialEq)]` to be usable in patterns
LL |
LL | const A: &[B] = &[];
| ------------- constant defined here
...
LL | A => (),
| ^ constant of non-structural type
|
= note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details
```
