It sees them as regular impls; the details are abstracted. It's beautiful for the IDE layer, and less beautiful for `hir`, so this is a big change.
Some small differences still exist:
- We show builtin derives impl (to the IDE layer) as if they have had no generic parameters. It is possible to show the parameters, but that means also having to handle fake impls in `TypeParam` etc., and the benefit is questionable.
- Getting the fn *def* type of a method of a builtin derive impl is not supported, as there is no real `FunctionId`, therefore no `CallableDefId`. The trait method is returned instead. Note: getting the fn *ptr* type of the method is supported well.
- Builtin derive impls and their methods do not fully support `HasSource`, because, well, they have no source (at least, not in the form of `ast::Impl` and `ast::Fn`). To support them, we use the derive's `TextRange` where possible, and the trait method's source when not.
It's important to note that the def map still records the `MacroCallId`. I have doubts over this, as this means it's very easy to create the queries we don't want to create, but it does make things more convenient. In particular, a nicety of this setup is that even "Expand macro recursively" works (it creates the macro input/output query, but given that they will only be created when the user invokes the command, that does not seem to be a problem).
And remove it when needed, the opposite of what was previously, where we stored without a tuple and tupled for the solver (because it requires that).
Because this is what rustc does, and generally, the closer we follow rustc, the easier our lives become.
The weird name `signature_unclosure()` also comes from rustc.
Rollup of 3 pull requests
Successful merges:
- rust-lang/rust#150141 (Misc cleanups from reading some borrowck code)
- rust-lang/rust#150297 (Fix compile issue in Vita libstd)
- rust-lang/rust#150341 (Fix some divergences with the cg_clif subtree)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix some divergences with the cg_clif subtree
For some reason git-subtree incorrectly synced those changes.
r? `@ghost`
`@rustbot` label +A-codegen +A-cranelift +T-compiler
Fix compile issue in Vita libstd
Unfortunately it looks like the Vita libc does not support
the "utimensat" function, which is needed for setting file times.
To fix the build, this commit marks Vita as unsupported for the
function that sets the file times.
Rollup of 3 pull requests
Successful merges:
- rust-lang/rust#150311 (Avoid using env::temp when linking a binary)
- rust-lang/rust#150336 (Disable f16 on LoongArch for LLVM < 21)
- rust-lang/rust#150338 (Include rustc version in ICE messages)
r? `@ghost`
`@rustbot` modify labels: rollup
Include rustc version in ICE messages
Rather than only including them in the ICE file. Not every user includes the ICE file in their bug reports, nor do they always list the rustc version.
Disable f16 on LoongArch for LLVM < 21
The `f16` type works on the LoongArch target starting from LLVM 21. However, the current minimum supported external LLVM version is 20, so `f16` must not be enabled on LoongArch for LLVM version < 21.
Avoid using env::temp when linking a binary
This keeps all build artefacts (even temporary ones) within the build directory.
Fixesrust-lang/rust#139963
The `f16` type works on the LoongArch target starting from LLVM 21.
However, the current minimum supported external LLVM version is 20,
so `f16` must not be enabled on LoongArch for LLVM version < 21.
mir_build: Classify `TestableCase::Constant` into multiple sub-kinds
In match lowering, when choosing a test for a `TestableCase::Constant`, there is some ad-hoc logic for inspecting the pattern type and deciding what kind of test is suitable. There is also some very similar logic later, when partitioning cases into buckets based on the chosen test.
Instead of having that ad-hoc logic in multiple places, I think it's better to perform an up-front classification when lowering `thir::PatKind::Constant` to `TestableCase::Constant`, and then have the later steps simply match on an enum variant.
There should be no change to the resulting built MIR.
(I will note that the logic/invariants involved are a bit unclear, so there is a risk of accidental minor differences.)
Correct terminology in Clone
I think the current wording around Clone here is confusing:
- "Rust does not allow you to reimplement `Copy`" - reimplement isn't a piece of Rust terminology, but as written it sounds like you can't write `impl Copy for X`, which you can.
- "you may reimplement `Clone`" - again reimplement isn't really a thing that you do to a trait, the distinction is between manually implementing and deriving.
- "you can automatically make anything `Copy` be `Clone` as well" - you don't have a choice about it, so it doesn't really make sense to say you "can ... make" this happen.
Remap both absolute and relative paths when building `rustc` and `std`
Turns out [#150110](https://github.com/rust-lang/rust/issues/150110) didn't work as expected, because when the standard library sources are present, we [helpfully un-remap the paths](https://github.com/rust-lang/rust/blob/e951f470d76febcc6f0a5b409c509eb77450a336/compiler/rustc_metadata/src/rmeta/decoder.rs#L1656-L1702) to the local directory of the user, including when we are building the compiler and standard library it-self (duh!), and since those paths are absolute (not relative), our purely relative remapping didn't pick them up.
This behavior wasn't a issue before because the un-remap logic immediately tries to remap them again, and since we had the absolute remapping we would just remap them to the the same thing.
To fix that issue I've adjusted our remapping to remap both the absolute and relative paths when building `rustc` and `std`, as well as added a run-make to make sure we don't regress it again (with a new `needs-std-remap-debuginfo` directive).
r? `@jieyouxu`
Update bors configuration
Updates the configuration of bors to bring it up to speed with homu, in preparation for https://github.com/rust-lang/infra-team/issues/168. Mirrors configuration from homu's [configuration file](https://github.com/rust-lang/homu/blob/master/cfg.production.toml#L46).
This PR also enables reporting of merge conflicts, so that we can test this part of bors on `rust-lang/rust`. The merge conflict reports will be duplicated (until/unless we disable it in homu), but that hopefully shouldn't be such a big deal.
r? ``@marcoieni``
Tidying up tests/ui/issues 15 tests [6/N]
> [!NOTE]
> Intermediate commits are intended to help review, but will be squashed add comment commit prior to merge.
part of rust-lang/rust#133895
r? Kivooeo
Fix ICE in normalization during closure capture analysis (#149746)
This fixes an internal compiler error that occurred when normalizing associated types during closure capture analysis.
The Fix: Modified rustc_middle/src/ty/normalize_erasing_regions.rs to gracefully handle projection normalization failures instead of panicking when analyzing closure captures.
Regression Test: Added tests/ui/associated-types/normalization-ice-issue-149746.rs, a reproduction case involving complex associated type projections (<() as Owner>::Ty<T>) that previously crashed the compiler. Verified it now emits a standard type error (E0277).
Fixesrust-lang/rust#149746
MGCA: Support struct expressions without intermediary anon consts
r? oli-obk
tracking issue: rust-lang/rust#132980Fixesrust-lang/rust#127972Fixesrust-lang/rust#137888Fixesrust-lang/rust#140275
due to delaying a bug instead of ICEing in HIR ty lowering.
### High level goal
Under `feature(min_generic_const_args)` this PR adds another kind of const argument. A struct/variant construction const arg kind. We represent the values of the fields as themselves being const arguments which allows for uses of generic parameters subject to the existing restrictions present in `min_generic_const_args`:
```rust
fn foo<const N: Option<u32>>() {}
trait Trait {
#[type_const]
const ASSOC: usize;
}
fn bar<T: Trait, const N: u32>() {
// the initializer of `_0` is a `N` which is a legal const argument
// so this is ok.
foo::<{ Some::<u32> { 0: N } }>();
// this is allowed as mgca supports uses of assoc consts in the
// type system. ie `<T as Trait>::ASSOC` is a legal const argument
foo::<{ Some::<u32> { 0: <T as Trait>::ASSOC } }>();
// this on the other hand is not allowed as `N + 1` is not a legal
// const argument
foo::<{ Some::<u32> { 0: N + 1 } }>();
}
```
This PR does not support uses of const ctors, e.g. `None`. And also does not support tuple constructors, e.g. `Some(N)`. I believe that it would not be difficult to add support for such functionality after this PR lands so have left it out deliberately.
We currently require that all generic parameters on the type being constructed be explicitly specified. I haven't really looked into why that is but it doesn't seem desirable to me as it should be legal to write `Some { ... }` in a const argument inside of a body and have that desugar to `Some::<_> { ... }`. Regardless this can definitely be a follow-up PR and I assume this is some underlying consistency with the way that elided args are handled with type paths elsewhere.
This PRs implementation of supporting struct expressions is somewhat incomplete. We don't handle `Foo { ..expr }` at all and aren't handling privacy/stability. The printing of `ConstArgKind::Struct` HIR nodes doesn't really exist either :')
I've tried to keep the implementation here somewhat deliberately incomplete as I think a number of these issues are actually quite small and self contained after this PR lands and I'm hoping it could be a good set of issues to mentor newer contributors on 🤔 I just wanted the "bare minimum" required to actually demonstrate that the previous changes are "necessary".
### `ValTree` now recurse through `ty::Const`
In order to actually represent struct/variant construction in `ty::Const` without going through an anon const we would need to introduce some new `ConstKind` variant. Let's say some hypothetical `ConstKind::ADT(Ty<'tcx>, List<Const<'tcx>>)`.
This variant would represent things the same way that `ValTree` does with the first element representing the `VariantIdx` of the enum (if its an enum), and then followed by a list of field values in definition order.
This *could* work but there are a few reasons why it's suboptimal.
First it would mean we have a second kind of `Const` that can be normalized. Right now we only have `ConstKind::Unevaluated` which possibly needs normalization. Similarly with `TyKind` we *only* have `TyKind::Alias`. If we introduced `ConstKind::ADT` it would need to be normalized to a `ConstKind::Value` eventually. This feels to me like it has the potential to cause bugs in the long run where only `ConstKind::Unevaluated` is handled by some code paths.
Secondly it would make type equality/inference be kind of... weird... It's desirable for `Some { 0: ?x } eq Some { 0: 1_u32 }` to result in `?x=1_u32`. I can't see a way for this to work with this `ConstKind::ADT` design under the current architecture for how we represent types/consts and generally do equality operations.
We would need to wholly special case these two variants in type equality and have a custom recursive walker separate from the existing architecture for doing type equality. It would also be somewhat unique in that it's a non-rigid `ty::Const` (it can be normalized more later on in type inference) while also having somewhat "structural" equality behaviour.
Lastly, it's worth noting that its not *actually* `ConstKind::ADT` that we want. It's desirable to extend this setup to also support tuples and arrays, or even references if we wind up supporting those in const generics. Therefore this isn't really `ConstKind::ADT` but a more general `ConstKind::ShallowValue` or something to that effect. It represents at least one "layer" of a types value :')
Instead of doing this implementation choice we instead change `ValTree::Branch`:
```rust
enum ValTree<'tcx> {
Leaf(ScalarInt),
// Before this PR:
Branch(Box<[ValTree<'tcx>]>),
// After this PR
Branch(Box<[Const<'tcx>]>),
}
```
The representation for so called "shallow values" is now the same as the representation for the *entire* full value. The desired inference/type equality behaviour just falls right out of this. We also don't wind up with these shallow values actually being non-rigid. And `ValTree` *already* supports references/tuples/arrays so we can handle those just fine.
I think in the future it might be worth considering inlining `ValTree` into `ty::ConstKind`. E.g:
```rust
enum ConstKind {
Scalar(Ty<'tcx>, ScalarInt),
ShallowValue(Ty<'tcx>, List<Const<'tcx>>),
Unevaluated(UnevaluatedConst<'tcx>),
...
}
```
This would imply that the usage of `ValTree`s in patterns would now be using `ty::Const` but they already kind of are anyway and I think that's probably okay in the long run. It also would mean that the set of things we *could* represent in const patterns is greater which may be desirable in the long run for supporting things such as const patterns of const generic parameters.
Regardless, this PR doesn't actually inline `ValTree` into `ty::ConstKind`, it only changes `Branch` to recurse through `Const`. This change could be split out of this PR if desired.
I'm not sure if there'll be a perf impact from this change. It's somewhat plausible as now all const pattern values that have nesting will be interning a lot more `Ty`s. We shall see :>
### Forbidding generic parameters under mgca
Under mgca we now allow all const arguments to resolve paths to generic parameters. We then *later* actually validate that the const arg should be allowed to access generic parameters if it did wind up resolving to any.
This winds up just being a lot simpler to implement than trying to make name resolution "keep track" of whether we're inside of a non-anon-const const arg and then encounter a `const { ... }` indicating we should now stop allowing resolving to generic parameters.
It's also somewhat in line with what we'll need for a `feature(generic_const_args)` where we'll want to decide whether an anon const should have any generic parameters based off syntactically whether any generic parameters were used. Though that design is entirely hypothetical at this point :)
### Followup Work
- Make HIR ty lowering check whether lowering generic parameters is supported and if not lower to an error type/const. Should make the code cleaner, fix some other bugs, and maybe(?) recover perf since we'll be accessing less queries which I think is part of the perf regression of this PR
- Make the ValTree setup less scuffed. We should find a new name for `ConstKind::Value` and the `Val` part of `ValTree` and `ty::Value` as they no longer correspond to a fully normalized structure. It may also be worth looking into inlining `ValTreeKind` into `ConstKind` or atleast into `ty::Value` or sth 🤔
- Support tuple constructors and const constructors not just struct expressions.
- Reduce code duplication between HIR ty lowering's handling of struct expressions, and HIR typeck's handling of struct expressions
- Try fix perf https://github.com/rust-lang/rust/pull/149114#issuecomment-3668038853. Maybe this will clear up once we clean up `ValTree` a bit and stop doing double interning and whatnot
Lukas Wirth