Commit Graph

1313 Commits

Author SHA1 Message Date
Michael Goulet
c13bd83528 squash OpaqueTy and ProjectionTy into AliasTy 2022-12-13 17:40:27 +00:00
Michael Goulet
5c6afb850c ProjectionTy.item_def_id -> ProjectionTy.def_id 2022-12-13 17:34:44 +00:00
Michael Goulet
7f3af72606 Use ty::OpaqueTy everywhere 2022-12-13 17:29:26 +00:00
bors
109cccbe4f Auto merge of #105350 - compiler-errors:faster-binder-relate, r=oli-obk
Fast-path some binder relations

A simpler approach than #104598

Fixes #104583

r? types
2022-12-13 07:10:53 +00:00
Michael Goulet
5dea1d1c6e EarlyBinder nits 2022-12-13 04:53:36 +00:00
Michael Goulet
2025a96ee1 Fast path some binder relations 2022-12-13 03:17:14 +00:00
Takayuki Maeda
ee40a67cd9 remove unnecessary uses of clone 2022-12-13 02:06:24 +09:00
Boxy
dd19656df3 fold instead of obliterating args 2022-12-12 14:30:01 +00:00
Matthias Krüger
6111a7345b
Rollup merge of #105443 - compiler-errors:move-more, r=oli-obk
Move some queries and methods

Each commit's title should be self-explanatory. Motivated to break up some large, general files and move queries into leaf crates.
2022-12-09 07:25:46 +01:00
Matthias Krüger
086bdbbd73
Rollup merge of #104922 - estebank:fur-elize, r=oli-obk
Detect long types in E0308 and write them to disk

On type error with long types, print an abridged type and write the full type to disk.

Print the widest possible short type while still fitting in the terminal.
2022-12-08 12:57:28 +01:00
Michael Goulet
3b9daac6a2 Move some suggestions from error_reporting to error_reporting::suggest 2022-12-08 05:58:30 +00:00
Michael Goulet
da929fa63c Make get_impl_future_output_ty work with AFIT 2022-12-05 17:34:42 +00:00
mejrs
a7838d8bd7 Always evaluate vecs of subdiagnostics eagerly 2022-12-04 01:13:21 +01:00
Yuki Okushi
7d4af8852c
Rollup merge of #105188 - compiler-errors:verbose-ty-err, r=TaKO8Ki
Don't elide type information when printing E0308 with `-Zverbose`

When we pass `-Zverbose`, we kinda expect for all `_` to be replaced with more descriptive information, for example --

```
   = note: expected fn pointer `fn(_, u32)`
                 found fn item `fn(_, i32) {foo}`
```

Where `_` is the "identical" part of the fn signatures, now gets rendered as:

```
   = note: expected fn pointer `fn(i32, u32)`
                 found fn item `fn(i32, i32) {foo}`
```
2022-12-03 12:51:30 +09:00
Michael Goulet
5c642d7d1c Don't elide information when printing E0308 with Zverbose 2022-12-02 21:01:59 +00:00
Matthias Krüger
8e0d83a70c
Rollup merge of #105185 - compiler-errors:normalize_fn_sig-in-err-ctxt, r=lcnr
Move `normalize_fn_sig` to `TypeErrCtxt`

r? `@lcnr`
2022-12-02 21:22:50 +01:00
Michael Goulet
ffca711760 Move normalize_fn_sig to TypeErrCtxt 2022-12-02 19:29:14 +00:00
Michael Goulet
e45daa9856 Drive-by: remove unused type alias 2022-12-01 19:00:09 +00:00
bors
90711a86e5 Auto merge of #99814 - aliemjay:patch-2, r=jackh726
fix universe map in ifcx.instantiate_canonical_*

Previously, `infcx.instantiate_canonical_*` maps the root universe in `canonical` into `ty::UniverseIndex::Root`, I think because it assumes it works with a fresh `infcx` but this is not true for the use cases in mir typeck. Now the root universe is mapped into `infcx.universe()`.

I catched this accidentally while reviewing the code. I'm not sure if this is the right fix or if it is really a bug!
2022-11-30 14:03:36 +00:00
bors
e0098a5cc3 Auto merge of #105012 - WaffleLapkin:into, r=oli-obk
Make `tcx.mk_const` more permissive wrt `kind` argument (`impl Into`)

r? `@oli-obk` you've asked for this >:)
2022-11-29 13:28:44 +00:00
Esteban Küber
360c0a7a3e Tweak shortening logic to be less trigger happy 2022-11-28 14:08:19 -08:00
Esteban Küber
7674edeeba Detect long types in E0308 and write them to disk
On type error with long types, print an abridged type and write the full
type to disk.

Print the widest possible short type while still fitting in the
terminal.
2022-11-28 14:08:18 -08:00
Maybe Waffle
f4d00fe785 Remove Const::from_value
...it's just `mk_const` but without the sparcles
2022-11-28 17:28:30 +00:00
Maybe Waffle
26b87bf8ff Simplify calls to tcx.mk_const
`mk_const(ty::ConstKind::X(...), ty)` can now be simplified to
`mk_cosnt(...,                   ty)`.

I searched with the following regex: \mk_const\([\n\s]*(ty::)?ConstKind\
I've left `ty::ConstKind::{Bound, Error}` as-is, they seem clearer this
way.
2022-11-28 17:27:20 +00:00
Maybe Waffle
7087d9b2a0 Remove tcx.mk_const_var
... `tcx.mk_const` can now be used instead
2022-11-28 17:27:20 +00:00
Matthias Krüger
60d136000e
Rollup merge of #104936 - cjgillot:self-rpit-orig-too, r=oli-obk
Ignore bivariant parameters in test_type_match.

https://github.com/rust-lang/rust/pull/103491 made opaque types bivariant with respect of some of their lifetime parameters.  Because of this bivariance, some lifetime variables were not unified to anything during borrowck, and were considered as unequal by borrowck type test.

This PR makes type test ignore the bivariant parameters in test_type_match.

Fixes https://github.com/rust-lang/rust/issues/104815

r? `@oli-obk`
2022-11-28 17:25:47 +01:00
Dylan DPC
8a84dd8fcc
Rollup merge of #104890 - lcnr:small-cleanup, r=fee1-dead
small method code cleanup
2022-11-28 15:42:11 +05:30
Dylan DPC
f90484df8a
Rollup merge of #104732 - WaffleLapkin:from_def_idn't, r=compiler-errors
Refactor `ty::ClosureKind` related stuff

I've tried to fix all duplication and weirdness, but if I missed something do tell :p

r? `@compiler-errors`
2022-11-28 15:42:10 +05:30
Matthias Krüger
86304f5149
Rollup merge of #104976 - WaffleLapkin:move_comments, r=cjgillot
Prefer doc comments over `//`-comments in compiler

Doc comments are generally nicer: they show up in the documentation, they are shown in IDEs when you hover other mentions of items, etc. Thus it makes sense to use them instead of `//`-comments.
2022-11-27 22:14:08 +01:00
bors
454784afba Auto merge of #104048 - cjgillot:split-lifetime, r=compiler-errors
Separate lifetime ident from lifetime resolution in HIR

Drive-by: change how suggested generic args are computed.
Fixes https://github.com/rust-lang/rust/issues/103815

I recommend reviewing commit-by-commit.
2022-11-27 14:30:19 +00:00
Maybe Waffle
1d42936b18 Prefer doc comments over //-comments in compiler 2022-11-27 11:19:04 +00:00
Maybe Waffle
5ba0056346 Use TyCtxt::is_fn_trait is a couple more places 2022-11-27 07:20:28 +00:00
Maybe Waffle
881862ecb7 Rename fn_trait_kind_from_{from_lang=>def_id} to better convey meaning 2022-11-27 07:14:49 +00:00
Guillaume Gomez
4019c8aaf7
Rollup merge of #104921 - compiler-errors:no-binder-on-fut-ty, r=cjgillot
Remove unnecessary binder from `get_impl_future_output_ty`

We never construct an `async fn` with a higher-ranked `impl Future` bound anyways, and basically all the call-sites already skip the binder.
2022-11-26 17:47:24 +01:00
Guillaume Gomez
e6c83d9e42
Rollup merge of #104788 - compiler-errors:unresolved-ct-in-gen, r=fee1-dead
Do not record unresolved const vars in generator interior

Don't record types in the generator interior when we see unresolved const variables.

We already do this for associated types -- this is important to avoid unresolved inference variables in the generator results during writeback, since the writeback results get stable hashed in incremental mode.

Fixes #104787
2022-11-26 17:47:23 +01:00
Guillaume Gomez
a2e485c25c
Rollup merge of #104786 - WaffleLapkin:amp-mut-help, r=compiler-errors
Use the power of adding helper function to simplify code w/ `Mutability`

r? `@compiler-errors`
2022-11-26 17:47:23 +01:00
Camille GILLOT
89afda7811 Ignore bivariant parameters in test_type_match. 2022-11-26 09:50:01 +00:00
Michael Goulet
6210812494 Do not record unresolved const vars in generator interior 2022-11-26 05:38:43 +00:00
Michael Goulet
1472b38039 Remove unnecessary binder from get_impl_future_output_ty 2022-11-26 05:22:52 +00:00
bors
aff003becd Auto merge of #99798 - JulianKnodt:ac1, r=BoxyUwU
Add `ConstKind::Expr`

Starting to implement `ty::ConstKind::Abstract`, most of the match cases are stubbed out, some I was unsure what to add, others I didn't want to add until a more complete implementation was ready.

r? `@lcnr`
2022-11-25 22:56:59 +00:00
lcnr
a215b7b4df remove TypeError::ObjectUnsafeCoercion 2022-11-25 16:39:23 +01:00
Boxy
2ac5d91d63 Make expand_abstract_consts infallible 2022-11-25 09:28:44 +00:00
kadmin
5bb1a9febc Add expand_abstract_const
Adds the ability to directly expand a const to an expr without having to deal with intermediate
steps.
2022-11-25 09:28:43 +00:00
kadmin
f9750c1554 Add empty ConstKind::Abstract
Initial pass at expr/abstract const/s

Address comments

Switch to using a list instead of &[ty::Const], rm `AbstractConst`

Remove try_unify_abstract_consts

Update comments

Add edits

Recurse more

More edits

Prevent equating associated consts

Move failing test to ui

Changes this test from incremental to ui, and mark it as failing and a known bug.
Does not cause the compiler to ICE, so should be ok.
2022-11-25 09:28:43 +00:00
Santiago Pastorino
974e2837bb
Introduce PredicateKind::Clause 2022-11-25 00:04:54 -03:00
Santiago Pastorino
1930c77de1
Remove normalize_projection_type 2022-11-24 09:02:55 -03:00
Maybe Waffle
8195e12dd9 Add Mutability::ref_prefix_str, order Mutability, simplify code 2022-11-23 19:36:27 +00:00
Camille GILLOT
fb7d25e978 Separate lifetime ident from resolution in HIR. 2022-11-23 19:33:06 +00:00
Manish Goregaokar
53eab246db
Rollup merge of #103488 - oli-obk:impl_trait_for_tait, r=lcnr
Allow opaque types in trait impl headers and rely on coherence to reject unsound cases

r? ````@lcnr````

fixes #99840
2022-11-22 22:54:38 -05:00
bors
b7463e8bdb Auto merge of #103578 - petrochenkov:nofict, r=nagisa
Unreserve braced enum variants in value namespace

With this PR braced enum variants (`enum E { V { /*...*/ } }`) no longer take a slot in value namespace, so the special case mentioned in the note in https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md#braced-structs is removed.

Report - https://github.com/rust-lang/rust/pull/103578#issuecomment-1292594900.
2022-11-22 10:17:09 +00:00
Oli Scherer
7658e0fccf Stop passing the self-type as a separate argument. 2022-11-21 20:39:46 +00:00
Oli Scherer
ec8d01fdcc Allow iterators instead of requiring slices that will get turned into iterators 2022-11-21 20:33:55 +00:00
Oli Scherer
6f77c97b38 Assert that various types have the right amount of generic args and fix the sites that used the wrong amount 2022-11-21 20:31:59 +00:00
Vadim Petrochenkov
7a5376d23c Unreserve braced enum variants in value namespace 2022-11-21 22:40:06 +03:00
Oli Scherer
c16a90f5e3 Test generalization during coherence 2022-11-21 16:47:29 +00:00
Oli Scherer
11adf03790 Add some more assertions for type relations not used during coherence 2022-11-21 16:38:49 +00:00
Oli Scherer
7301cd7844 Type generalization should not look at opaque type in coherence 2022-11-21 16:38:23 +00:00
Oli Scherer
11ae334f07 Remove a function that doesn't actually do anything 2022-11-21 16:37:57 +00:00
Oli Scherer
f42e490d6f Register obligations from type relation 2022-11-21 16:37:53 +00:00
Oli Scherer
9a8e1eea7a Move a field around 2022-11-21 16:35:23 +00:00
Oli Scherer
ae80c764d4 Add an always-ambiguous predicate to make sure that we don't accidentlally allow trait resolution to prove false things during coherence 2022-11-21 16:35:04 +00:00
Oli Scherer
94fe30ff2f Treat different opaque types of the same def id as equal during coherence 2022-11-21 16:06:07 +00:00
bors
1cbc45942d Auto merge of #104673 - matthiaskrgr:rollup-85f65ov, r=matthiaskrgr
Rollup of 9 pull requests

Successful merges:

 - #104420 (Fix doc example for `wrapping_abs`)
 - #104499 (rustdoc JSON: Use `Function` everywhere and remove `Method`)
 - #104500 (`rustc_ast`: remove `ref` patterns)
 - #104511 (Mark functions created for `raw-dylib` on x86 with DllImport storage class)
 - #104595 (Add `PolyExistentialPredicate` type alias)
 - #104605 (deduplicate constant evaluation in cranelift backend)
 - #104628 (Revert "Update CI to use Android NDK r25b")
 - #104662 (Streamline deriving on packed structs.)
 - #104667 (Revert formatting changes of a test)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-11-21 15:22:54 +00:00
Matthias Krüger
844e3fb928
Rollup merge of #104595 - compiler-errors:poly-existential-predicate, r=lcnr
Add `PolyExistentialPredicate` type alias

Wrapping `ExistentialPredicate`s in a binder is very common, and this alias already exists for the `PolyExistential{TraitRef,Projection}` types.
2022-11-21 14:11:11 +01:00
bors
7fe6f36224 Auto merge of #103491 - cjgillot:self-rpit, r=oli-obk
Support using `Self` or projections inside an RPIT/async fn

I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.

The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`.  This PR changes the scheme
```rust
impl<'a> Foo<'a> {
    fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}

opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
    // OLD
    fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
                             ^^^^^^^ the `Self` becomes `Foo<'static>`

    // NEW
    fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
                             ^^ the `Self` stays `Foo<'a>`
}
```

There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.

This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more.  The same trick allows to use projections like `T::Assoc` where `Self` is allowed.  The feature is gated behind a `impl_trait_projections` feature gate.

The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.

For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.

Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.

Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck.  In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.

r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
2022-11-21 12:17:03 +00:00
Dylan DPC
7f35493e99
Rollup merge of #104554 - BoxyUwU:less_unchecked_pls, r=lcnr
Use `ErrorGuaranteed::unchecked_claim_error_was_emitted` less

there are only like 3 or 4 call sites left after this but it wasnt obvious to me how to remove them
2022-11-19 11:54:45 +05:30
Dylan DPC
00876c68c4
Rollup merge of #104411 - lcnr:bivariance-nll, r=compiler-errors
nll: correctly deal with bivariance

fixes #104409

when in a bivariant context, relating stuff should always trivially succeed. Also changes the mir validator to correctly deal with higher ranked regions.

r? types cc ``@RalfJung``
2022-11-19 11:54:44 +05:30
Michael Goulet
c36ff28d42 drive-by: PolyExistentialPredicate 2022-11-19 04:04:27 +00:00
Boxy
9ed348376f require an ErrorGuaranteed to taint infcx with errors 2022-11-18 13:25:17 +00:00
Boxy
1c48039a87 rename is_tainted_by_errors 2022-11-18 13:25:17 +00:00
Boxy
9c510048fd InferCtxt::is_tainted_by_errors returns ErrorGuaranteed 2022-11-18 13:25:17 +00:00
Oli Scherer
4f11f3b257 Convert predicates into Predicate in the Obligation constructor 2022-11-16 09:25:19 +00:00
lcnr
6aa611a84c mv utility methods into separate module 2022-11-15 13:50:13 +01:00
lcnr
45f441a7b4 nll: correctly deal with bivariance 2022-11-15 13:34:08 +01:00
Camille GILLOT
3afec247cb Deduplicate visitor. 2022-11-14 18:20:49 +00:00
Camille GILLOT
d470ac9334 Drop relate_opaque_item_substs. 2022-11-14 18:05:14 +00:00
Camille GILLOT
5fc261e9a0 Inherit generics for impl-trait. 2022-11-12 09:59:36 +00:00
Dylan DPC
662df1ec86
Rollup merge of #104206 - compiler-errors:ocx-more-2, r=lcnr
Remove `save_and_restore_in_snapshot_flag`, use `ObligationCtxt` more

r? ```@lcnr```
2022-11-12 12:02:52 +05:30
bors
11fa0850f0 Auto merge of #103636 - chenyukang:yukang/fix-103587-sugg-if-let, r=jackh276,davidtwco
Recover from common if let syntax mistakes/typos

Fixes #103587
2022-11-10 05:19:10 +00:00
Michael Goulet
ed6a7cc228 Remove save_and_restore_in_snapshot_flag 2022-11-09 22:58:39 +00:00
bors
cc9b259b5e Auto merge of #103723 - CastilloDel:master, r=jackh726
Remove allow(rustc::potential_query_instability) in rustc_trait_selection

Related to https://github.com/rust-lang/rust/issues/84447

This PR needs to be benchmarked to check for regressions.
2022-11-09 13:45:27 +00:00
bors
bc2504a83c Auto merge of #103171 - jackh726:gen-interior-hrtb-error, r=cjgillot
Better error for HRTB error from generator interior

cc #100013

This is just a first pass at an error. It could be better, and shouldn't really be emitted in the first place. But this is better than what was being emitted before.
2022-11-09 02:02:28 +00:00
CastilloDel
755ca4b9aa Reduce the scope of allow(rustc::potential_query_instability) in rustc_trait_selection
Make InferCtxtExt use a FxIndexMap

This should be faster, because the map is only being used to iterate,
which is supposed to be faster with the IndexMap

Make the user_computed_preds use an IndexMap

It is being used mostly for iteration, so the change shouldn't result in
a perf hit

Make the RegionDeps fields use an IndexMap

This change could be a perf hit. Both `larger` and `smaller` are used
for iteration, but they are also used for insertions.

Make types_without_default_bounds use an IndexMap

It uses extend, but it also iterates and removes items. Not sure if
this will be a perf hit.

Make InferTtxt.reported_trait_errors use an IndexMap

This change brought a lot of other changes. The map seems to have been
mostly used for iteration, so the performance shouldn't suffer.

Add FIXME to change ProvisionalEvaluationCache.map to use an IndexMap

Right now this results in a perf hit. IndexMap doesn't have
the `drain_filter` API, so in `on_completion` we now need to iterate two
times over the map.
2022-11-08 19:41:48 +01:00
yukang
9e7d2287cd use subdiagnostic for sugesting add let 2022-11-08 16:25:37 +08:00
yukang
667b15bb0e fix #103587, Recover from common if let syntax mistakes/typos 2022-11-08 14:10:04 +08:00
Dylan DPC
77a44ab568
Rollup merge of #103865 - compiler-errors:fallback-has-occurred-tracking, r=eholk
Move `fallback_has_occurred` state tracking to `FnCtxt`

Removes a ton of callsites that defaulted to `false`
2022-11-08 11:23:51 +05:30
Jack Huey
3c71fafd6d Add a known that this is a known limitation 2022-11-07 17:52:08 -05:00
Jack Huey
cececca7c7 Get spans for a couple more region types, add some optimizations, and extend test 2022-11-07 17:39:30 -05:00
Jack Huey
00e314d5ed Add an optional Span to BrAnon and use it to print better error for HRTB error from generator interior 2022-11-07 17:39:29 -05:00
bors
ca08a32655 Auto merge of #103218 - CastilloDel:infer, r=jackh726
Remove #![allow(rustc::potential_query_instability)] from rustc_infer

Related to #84447

This PR probably needs to be benchmarked to check for regressions.
2022-11-07 07:38:05 +00:00
Michael Goulet
bc345d7bd0 Move fallback_has_occurred to FnCtxt 2022-11-06 02:40:25 +00:00
bors
a4ab2e0643 Auto merge of #103975 - oli-obk:tracing, r=jackh726
Some tracing and comment cleanups

Pulled out of https://github.com/rust-lang/rust/pull/101900 to see if that is the perf impact
2022-11-06 02:21:34 +00:00
Mateusz
c97fd8183a
Refactor tcx mk_const parameters. 2022-11-04 20:33:32 +00:00
Oli Scherer
44d1936d00 Some tracing and comment cleanups 2022-11-04 17:10:07 +00:00
Manish Goregaokar
69e705564d
Rollup merge of #103575 - Xiretza:suggestions-style-attr, r=davidtwco
Change #[suggestion_*] attributes to use style="..."

As discussed [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20tool_only_span_suggestion), this changes `#[(multipart_)suggestion_{short,verbose,hidden}(...)]` attributes to plain `#[(multipart_)suggestion(...)]` attributes with a `style = "{short,verbose,hidden}"` parameter.

It also adds a new style, `tool-only`, that corresponds to `tool_only_span_suggestion`/`tool_only_multipart_suggestion` and causes the suggestion to not be shown in human-readable output at all.

Best reviewed commit-by-commit, there's a bit of noise in there.

cc #100717 `@compiler-errors`
r? `@davidtwco`
2022-11-01 20:00:38 -04:00
bors
e70cbef0c5 Auto merge of #103590 - compiler-errors:ocx-more, r=lcnr
(almost) Always use `ObligationCtxt` when dealing with canonical queries

Hope this is a step in the right direction. cc rust-lang/types-team#50.

r? `@lcnr`
2022-11-01 12:15:10 +00:00
Nicholas Nethercote
c8c25ce5a1 Rename some OwnerId fields.
spastorino noticed some silly expressions like `item_id.def_id.def_id`.

This commit renames several `def_id: OwnerId` fields as `owner_id`, so
those expressions become `item_id.owner_id.def_id`.

`item_id.owner_id.local_def_id` would be even clearer, but the use of
`def_id` for values of type `LocalDefId` is *very* widespread, so I left
that alone.
2022-10-29 20:28:38 +11:00
CastilloDel
e9502010b4 Remove #![allow(rustc::potential_query_instability)] from rustc_infer
Change reported_violations to use IndexSet

It is being used to iterate and to insert, without a lot of lookups
so hopefully it won't be a perf hit

Change MiniGraph.nodes to use IndexSet

It is being used to iterate and to insert, without performing lookups
so hopefully it won't be a perf hit

Change RegionConstraintData.givens to a FxIndexSet

This might result in a perf hit. Remove was being used in `givens`,
and `FxIndexSet` doesn't allow calling remove without losing the
fixed iteration order. So it was necessary to change remove to
`shift_remove`, but this method is slower.

Change OpaqueTypesVisitor to use stable sets and maps

This could also be a perf hit.

Make TraitObject visitor use a stable set
2022-10-28 15:32:49 +02:00
Matthias Krüger
84663cee39
Rollup merge of #103641 - compiler-errors:issue-103624, r=cjgillot
Don't carry MIR location in `ConstraintCategory::CallArgument`

It turns out that `ConstraintCategory::CallArgument` cannot just carry a MIR location in it, since we may bubble them up to totally different MIR bodies.

So instead, revert the commit a6b5f95fb0, and instead just erase regions from the original `Option<Ty<'tcx>>` that it carried, so that it doesn't ICE with the changes in #103220.

Best reviewed in parts -- the first is just a revert, and the second is where the meaningful changes happen.

Fixes #103624
2022-10-28 07:06:43 +02:00
Michael Goulet
dce44faf5b Revert "Make ClosureOutlivesRequirement not rely on an unresolved type"
This reverts commit a6b5f95fb0.
2022-10-27 16:15:11 +00:00
Michael Goulet
d793d80cf7 (almost) Always use ObligationCtxt when dealing with canonical queries 2022-10-27 15:43:33 +00:00
Matthias Krüger
16e74c78a1
Rollup merge of #103255 - oli-obk:opaque_wrong_eq_relation, r=compiler-errors
Clean up hidden type registration

work on https://github.com/rust-lang/rust/issues/101186

Actually passing down the relation and using it instead of `eq` for the hidden type comparison has *no* effect whatsoever and allows for no further improvements at the call sites. I decided the increased complexity was not worth it and thus did not include that change in this PR.

r? `@compiler-errors`
2022-10-27 15:03:55 +02:00
Michael Goulet
901649eeb7 No need to probe when relating opaques in nll_relate 2022-10-26 22:10:12 +00:00
Xiretza
cd621be782 Convert all #[suggestion_*] attributes to #[suggestion(style = "...")]
Using the following command:

find compiler/ -type f -name '*.rs' -exec perl -i -gpe \
    's/(#\[\w*suggestion)_(short|verbose|hidden)\(\s*(\S+,)?/\1(\3style = "\2",/g' \
    '{}' +
2022-10-26 15:04:09 +02:00
Oli Scherer
de5517c3ae Remove unneeded sub-comparison 2022-10-26 12:47:04 +00:00
Dylan DPC
785828744c
Rollup merge of #103416 - compiler-errors:rpit-named, r=cjgillot
Name the `impl Trait` in region bound suggestions

Slightly more descriptive message
2022-10-26 11:29:54 +05:30
Michael Goulet
726bf18d2d Name impl trait in region bound suggestion 2022-10-25 16:37:11 +00:00
Oli Scherer
f3bd222ad9 Bubble the opaque type ordering int opaque type handling 2022-10-25 13:27:58 +00:00
Oli Scherer
14caf7396d Pull opaque type handling out of the type relating delegate 2022-10-25 13:27:04 +00:00
Michael Goulet
1727c00f1a Assert if inference vars are leaking from fully_resolve 2022-10-24 18:53:32 +00:00
bors
e64f1110c0 Auto merge of #103345 - Nilstrieb:diag-flat, r=compiler-errors
Flatten diagnostic slug modules

This makes it easier to grep for the slugs in the code.

See https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Localization.20infra.20interferes.20with.20grepping.20for.20error for more discussion about it.

This was mostly done with a few regexes and a bunch of manual work. This also exposes a pretty annoying inconsistency for the extra labels. Some of the extra labels are defined as additional properties in the fluent message (which makes them not prefixed with the crate name) and some of them are new fluent messages themselves (which makes them prefixed with the crate name). I don't know whether we want to clean this up at some point but it's useful to know.

r? `@davidtwco`
2022-10-23 09:06:39 +00:00
Nilstrieb
c65ebae221
Migrate all diagnostics 2022-10-23 10:09:44 +02:00
Matthias Krüger
ff689a1404
Rollup merge of #103355 - compiler-errors:rpitit-default-check, r=oli-obk
Handle return-position `impl Trait` in traits properly in `register_hidden_type`

The bounds that we get by calling `bound_explicit_item_bounds` from an RPITIT have projections, not opaques, but when we're *registering* an opaque, we want to treat it like an opaque.

Coincidentally fixes #102688 as well, which makes sense, since that was failing because we were inferring an opaque type to be equal to itself (opaque cycle error => "cannot resolve opaque type").

Fixes #103352

r? ```@oli-obk```
2022-10-23 08:14:31 +02:00
Matthias Krüger
b656f5e9a6
Rollup merge of #103354 - clubby789:escape-string-literals, r=compiler-errors
Escape string literals when fixing overlong char literal

Fixes #103323

````@rustbot```` label +A-diagnostics +A-suggestion-diagnostics
2022-10-23 08:14:31 +02:00
Michael Goulet
aa8931c612 Introduce subst_iter and subst_iter_copied on EarlyBinder 2022-10-22 06:52:12 +00:00
clubby789
ed40d46159 Properly escape quotes when suggesting switching between char/string literals 2022-10-22 02:37:15 +01:00
Michael Goulet
419fde7a38 Handle RPITITs properly in register_hidden_type 2022-10-21 14:57:01 +00:00
Dylan DPC
e11511dfa6
Rollup merge of #103051 - davidtwco:translation-tidying-up, r=compiler-errors
translation: doc comments with derives, subdiagnostic-less enum variants, more derive use

- Adds support for `doc` attributes in the diagnostic derives so that documentation comments don't result in the derive failing.
- Adds support for enum variants in the subdiagnostic derive to not actually correspond to an addition to a diagnostic.
- Made use of the derive in more places in the `rustc_ast_lowering`, `rustc_ast_passes`, `rustc_lint`, `rustc_session`, `rustc_infer` - taking advantage of recent additions like eager subdiagnostics, multispan suggestions, etc.

cc #100717
2022-10-21 17:29:58 +05:30
Michael Goulet
a6b5f95fb0 Make ClosureOutlivesRequirement not rely on an unresolved type 2022-10-19 17:10:59 +00:00
bors
a9d1cafa87 Auto merge of #102355 - lcnr:bye-bye-type-traversal, r=oli-obk
remove type traversal for mir constants

r? `@oli-obk` cc `@b-naber`
2022-10-17 14:19:28 +00:00
David Wood
913f597402 infer: use derive more
Signed-off-by: David Wood <david.wood@huawei.com>
2022-10-17 09:54:24 +01:00
lcnr
e8150fa60c mir constants: type traversing bye bye 2022-10-17 10:54:01 +02:00
Takayuki Maeda
0b6fa0d418 fix own_substs ICE 2022-10-16 22:24:27 +09:00
Rageking8
7122abaddf more dupe word typos 2022-10-14 12:57:56 +08:00
Yuki Okushi
0ace46f98c
Rollup merge of #102974 - Rageking8:fix-small-word-dupe-typos, r=JohnTitor
Fix small word dupe typos
2022-10-13 09:41:27 +09:00
Rageking8
d1982bd0af fix small word dupe typos 2022-10-13 00:53:46 +08:00
Niko Matsakis
70200ac190
Update compiler/rustc_infer/src/infer/canonical/mod.rs 2022-10-10 16:51:36 -04:00
David Wood
b4ac26289f errors: AddToDiagnostic::add_to_diagnostic_with
`AddToDiagnostic::add_to_diagnostic_with` is similar to the previous
`AddToDiagnostic::add_to_diagnostic` but takes a function that can be
used by the caller to modify diagnostic messages originating from the
subdiagnostic (such as performing translation eagerly).

`add_to_diagnostic` now just calls `add_to_diagnostic_with` with an
empty closure.

Signed-off-by: David Wood <david.wood@huawei.com>
2022-10-10 14:20:16 +01:00
Yuki Okushi
24424d0acb
Rollup merge of #102829 - compiler-errors:rename-impl-item-kind, r=TaKO8Ki
rename `ImplItemKind::TyAlias` to `ImplItemKind::Type`

The naming of this variant seems inconsistent given that this is not really a "type alias", and the associated type variant for `TraitItemKind` is just called `Type`.
2022-10-10 00:09:42 +09:00
Michael Goulet
70f3c79c50 ImplItemKind::TyAlias => ImplItemKind::Type 2022-10-09 07:09:57 +00:00
Cameron Steffen
283abbf0e7 Change InferCtxtBuilder from enter to build 2022-10-07 07:10:40 -05:00
Cameron Steffen
349415d1c6 Remove TypeckResults from InferCtxt 2022-10-07 07:06:19 -05:00
Cameron Steffen
4a68373217 Introduce TypeErrCtxt
TypeErrCtxt optionally has a TypeckResults so that InferCtxt doesn't
need to.
2022-10-07 07:06:16 -05:00
Dylan DPC
cec087a202
Rollup merge of #102496 - compiler-errors:into-suggestion, r=davidtwco
Suggest `.into()` when all other coercion suggestions fail

Also removes some bogus suggestions because we now short-circuit when offering coercion suggestions(instead of, for example, suggesting every one that could possibly apply)

Fixes #102415
2022-10-05 17:27:33 +05:30
Takayuki Maeda
45257962d3 stop suggesting adding generic args for turbofish 2022-10-05 16:58:29 +09:00
Michael Goulet
28eda9b18a Suggest .into() when all other coercion suggestions fail 2022-10-05 02:47:31 +00:00
Oli Scherer
c7b6ebdf7c It's not about types or consts, but the lack of regions 2022-10-04 14:10:44 +00:00
Nicholas Nethercote
f07d4efc45 Shrink hir::def::Res.
`Res::SelfTy` currently has two `Option`s. When the second one is `Some`
the first one is never consulted. So we can split it into two variants,
`Res::SelfTyParam` and `Res::SelfTyAlias`, reducing the size of `Res`
from 24 bytes to 12. This then shrinks `hir::Path` and
`hir::PathSegment`, which are the HIR types that take up the most space.
2022-09-29 08:44:52 +10:00
lcnr
1fc86a63f4 rustc_typeck to rustc_hir_analysis 2022-09-27 10:37:23 +02:00
Pietro Albini
3975d55d98
remove cfg(bootstrap) 2022-09-26 10:14:45 +02:00
bors
f5193a9fcc Auto merge of #95474 - oli-obk:tait_ub, r=jackh726
Neither require nor imply lifetime bounds on opaque type for well formedness

The actual hidden type can live arbitrarily longer than any individual lifetime and arbitrarily shorter than all but one of the lifetimes.

fixes #86218
fixes #84305

This is a **breaking change** but it is a necessary soundness fix
2022-09-25 19:15:26 +00:00
Matthias Krüger
16de1fddee
Rollup merge of #102016 - lcnr:given-OutlivesEnvironment, r=jackh726
implied_bounds: deal with inference vars

fixes #101951

while computing implied bounds for `<<T as ConstructionFirm>::Builder as BuilderFn<'_>>::Output` normalization replaces a projection with an inference var (adding a `Projection` obligation). Until we prove that obligation, this inference var remains unknown, which caused us to miss an implied bound necessary to prove that the unnormalized projection from the trait method signature is wf.

r? types
2022-09-25 09:32:07 +02:00
Takayuki Maeda
8fe936099a separate definitions and HIR owners
fix a ui test

use `into`

fix clippy ui test

fix a run-make-fulldeps test

implement `IntoQueryParam<DefId>` for `OwnerId`

use `OwnerId` for more queries

change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
2022-09-24 23:21:19 +09:00
bors
9a963e3bad Auto merge of #102056 - b-naber:unevaluated, r=lcnr
Introduce mir::Unevaluated

Previously the distinction between unevaluated constants in the type-system and in mir was not explicit and a little confusing. Probably better to introduce its own type for that.

r? `@lcnr`
2022-09-23 13:39:11 +00:00
b-naber
a705e65605 rename Unevaluated to UnevaluatedConst 2022-09-23 14:27:34 +02:00
bors
4d44e09cb1 Auto merge of #102165 - matthiaskrgr:rollup-n5oquhe, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #100734 (Split out async_fn_in_trait into a separate feature)
 - #101664 (Note if mismatched types have a similar name)
 - #101815 (Migrated the rustc_passes annotation without effect diagnostic infrastructure)
 - #102042 (Distribute rust-docs-json via rustup.)
 - #102066 (rustdoc: remove unnecessary `max-width` on headers)
 - #102095 (Deduplicate two functions that would soon have been three)
 - #102104 (Set 'exec-env:RUST_BACKTRACE=0' in const-eval-select tests)
 - #102112 (Allow full relro on powerpc64-unknown-linux-gnu)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-09-23 09:33:23 +00:00
Oli Scherer
59e285ff34 Report diagnostics at the actually actionable site 2022-09-23 08:00:02 +00:00
Matthias Krüger
c2d2535b84
Rollup merge of #101664 - mejrs:similarity, r=fee1-dead
Note if mismatched types have a similar name

If users get a type error between similarly named types, it will point out that these are actually different types, and where they were defined.
2022-09-23 04:29:16 +02:00
Matthias Krüger
b93c9a7d37
Rollup merge of #102128 - oli-obk:const_unification, r=lcnr
Const unification is already infallible, remove the error handling logic

r? `@lcnr`

is this expected to be used in the future? Right now it is dead code.
2022-09-22 21:34:53 +02:00
bors
89e4e1f1b3 Auto merge of #102139 - Dylan-DPC:rollup-ljlipt8, r=Dylan-DPC
Rollup of 8 pull requests

Successful merges:

 - #101598 (Update rustc's information on Android's sanitizers)
 - #102036 (Remove use of `io::ErrorKind::Other` in std)
 - #102037 (Make cycle errors recoverable)
 - #102069 (Skip `Equate` relation in `handle_opaque_type`)
 - #102076 (rustc_transmute: fix big-endian discriminants)
 - #102107 (Add missing space between notable trait tooltip and where clause)
 - #102119 (Fix a typo “pararmeter” in error message)
 - #102131 (Added which number is computed in compute_float.)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-09-22 15:18:35 +00:00
Dylan DPC
8bf533593d
Rollup merge of #102069 - compiler-errors:no-eq-in-register-opaque, r=oli-obk
Skip `Equate` relation in `handle_opaque_type`

r? ``@oli-obk``
2022-09-22 18:25:54 +05:30
Dylan DPC
d5ae6737bf
Rollup merge of #102037 - jyn514:normalize-docs, r=lcnr
Make cycle errors recoverable

In particular, this allows rustdoc to recover from cycle errors when normalizing associated types for documentation.

In the past, ```@jackh726``` has said we need to be careful about overflow errors: https://github.com/rust-lang/rust/pull/91430#issuecomment-983997013

> Off the top of my head, we definitely should be careful about treating overflow errors the same as
"not implemented for some reason" errors. Otherwise, you could end up with behavior that is
different depending on recursion depth. But, that might be context-dependent.

But cycle errors should be safe to unconditionally report; they don't depend on the recursion depth, they will always be an error whenever they're encountered.

Helps with https://github.com/rust-lang/rust/issues/81091.

r? ```@lcnr``` cc ```@matthewjasper```
2022-09-22 18:25:53 +05:30
bors
8ab71ab59f Auto merge of #100980 - compiler-errors:normalize-opaque-w-bound-vars, r=lcnr
Normalize opaques w/ bound vars

First, we reenable normalization of opaque types with escaping late bound regions to fix rust-lang/miri#2433. This essentially reverts #89285.

Second, we mitigate the perf regression found in #88862 by simplifying the way that we relate (sub and eq) GeneratorWitness types.

This relies on the fact that we construct these GeneratorWitness types somewhat particularly (with all free regions found in the witness types replaced with late bound regions) -- but those bound regions really should be treated as existential regions, not universal ones. Those two facts leads me to believe that we do not need to use the full `higher_ranked_sub` machinery to relate two generator witnesses. I'm pretty confident that this is correct, but I'm glad to discuss this further.
2022-09-22 12:47:31 +00:00
b-naber
9f3784df89 introduce mir::Unevaluated 2022-09-22 12:35:28 +02:00
Oli Scherer
13438ee29c Const unification is already infallible, remove the error handling logic 2022-09-22 08:20:13 +00:00
bors
7a8636c843 Auto merge of #100982 - fee1-dead-contrib:const-impl-requires-const-trait, r=oli-obk
Require `#[const_trait]` on `Trait` for `impl const Trait`

r? `@oli-obk`
2022-09-22 04:22:24 +00:00
Michael Goulet
02ad984d74 Comment, and bail early if bound vars list differs 2022-09-22 02:17:39 +00:00
Michael Goulet
d018144761 Optimize subtyping and equation of GeneratorWitness 2022-09-22 02:17:39 +00:00
bors
9062b780b3 Auto merge of #101558 - JhonnyBillM:session-diagnostic-to-diagnostic-handler-refactor, r=davidtwco
Move and rename `SessionDiagnostic` & `SessionSubdiagnostic` traits and macros

After PR #101434, we want to:
- [x] Move `SessionDiagnostic` to `rustc_errors`.
- [x] Add `emit_` methods that accept `impl SessionDiagnostic` to `Handler`.
- [x] _(optional)_ Rename trait `SessionDiagnostic` to `DiagnosticHandler`.
- [x] _(optional)_ Rename macro `SessionDiagnostic` to `DiagnosticHandler`.
- [x] Update Rustc Dev Guide and Docs to reflect these changes. https://github.com/rust-lang/rustc-dev-guide/pull/1460

Now I am having build issues getting the compiler to build when trying to rename the macro.

<details>
  <summary>See diagnostics errors and context when building.</summary>

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
  --> compiler/rustc_attr/src/session_diagnostics.rs:13:10
   |
13 |   #[derive(DiagnosticHandler)]
   |            ^^^^^^^^^^^^^^^^^ in this derive macro expansion
   |
  ::: /Users/jhonny/.cargo/registry/src/github.com-1ecc6299db9ec823/synstructure-0.12.6/src/macros.rs:94:9
   |
94 | /         pub fn $derives(
95 | |             i: $crate::macros::TokenStream
96 | |         ) -> $crate::macros::TokenStream {
   | |________________________________________- in this expansion of `#[derive(DiagnosticHandler)]`
   |
note: the lint level is defined here
  --> compiler/rustc_attr/src/lib.rs:10:9
   |
10 | #![deny(rustc::diagnostic_outside_of_impl)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

```

And also this one:

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
   --> compiler/rustc_attr/src/session_diagnostics.rs:213:32
    |
213 |         let mut diag = handler.struct_span_err_with_code(
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
```

> **Note**
> Can't find where this message is coming from, because you can see in [this experimental branch](https://github.com/JhonnyBillM/rust/tree/experimental/trying-to-rename-session-diagnostic-macro)  that I updated all errors and diags to say:
> error: diagnostics should only be created in **`DiagnosticHandler`**/`AddSubdiagnostic` impls
> and not:
> error: diagnostics should only be created in **`SessionDiagnostic`**/`AddSubdiagnostic` impls

</details>

I tried building the compiler in different ways (playing with the stages etc), but nothing worked.

## Question

**Do we need to build or do something different when renaming a macro and identifiers?**

For context, see experimental commit f2193a98b4 where the macro and symbols are renamed, but it doesn't compile.
2022-09-21 19:58:39 +00:00
Jhonny Bill Mena
e52e2344dc FIX - adopt new Diagnostic naming in newly migrated modules
FIX - ambiguous Diagnostic link in docs

UPDATE - rename diagnostic_items to IntoDiagnostic and AddToDiagnostic

[Gardening] FIX - formatting via `x fmt`

FIX - rebase conflicts. NOTE: Confirm wheather or not we want to handle TargetDataLayoutErrorsWrapper this way

DELETE - unneeded allow attributes in Handler method

FIX - broken test

FIX - Rebase conflict

UPDATE - rename residual _SessionDiagnostic and fix LintDiag link
2022-09-21 11:43:22 -04:00
Jhonny Bill Mena
191fac6826 UPDATE - rename AddSubdiagnostic trait to AddToDiagnostic 2022-09-21 11:39:53 -04:00
Jhonny Bill Mena
19b348fed4 UPDATE - rename DiagnosticHandler trait to IntoDiagnostic 2022-09-21 11:39:52 -04:00
Jhonny Bill Mena
5b8152807c UPDATE - move SessionDiagnostic from rustc_session to rustc_errors 2022-09-21 11:39:52 -04:00
Oli Scherer
86f1ca812b Improve diagnostic for adding more bounds to opaque types 2022-09-21 13:15:24 +00:00
Oli Scherer
36cb01deb3 Try out a perf optimization 2022-09-21 13:15:24 +00:00
Oli Scherer
615c9e8647 Inline substitution logic into declared_region_bounds 2022-09-21 13:11:54 +00:00
Oli Scherer
90b6744af7 Also collect bounds from the ParamEnv for opaque types 2022-09-21 13:11:54 +00:00
Oli Scherer
37928f5986 Neither require nor imply lifetime bounds on opaque type for well formedness 2022-09-21 13:11:54 +00:00
Oli Scherer
c8ecf09a25 Generalize projection_must_outlive 2022-09-21 12:51:33 +00:00
Oli Scherer
4d4cc4fe53 Generalize a helper to be useful for types other than projections 2022-09-21 12:51:33 +00:00
Oli Scherer
96b819a456 Inline a trivial function 2022-09-21 12:51:33 +00:00
Oli Scherer
759c04a00b Some tracing instrumentation cleanups 2022-09-21 11:31:55 +00:00
Oli Scherer
3d69d23a25 Split match out into a helper function 2022-09-21 11:31:55 +00:00
Michael Goulet
5b96e5e71a Skip Equate relation in handle_opaque_type 2022-09-20 20:57:02 +00:00
Michael Goulet
83e6128b57 Better binder treatment 2022-09-20 16:39:39 +00:00
Joshua Nelson
1512ce5925 Make cycle errors recoverable
In particular, this allows rustdoc to recover from cycle errors when normalizing associated types for documentation.

In the past, `@jackh726` has said we need to be careful about overflow errors:

> Off the top of my head, we definitely should be careful about treating overflow errors the same as
"not implemented for some reason" errors. Otherwise, you could end up with behavior that is
different depending on recursion depth. But, that might be context-dependent.

But cycle errors should be safe to unconditionally report; they don't depend on the recursion depth, they will always be an error whenever they're encountered.
2022-09-19 22:14:40 -05:00
mejrs
c65866000e Incorporate feedback 2022-09-19 17:19:45 +02:00
lcnr
71f8fd5c58 improve infer var handling for implied bounds 2022-09-19 15:13:34 +02:00
lcnr
647052fc04 remove the Subst trait, always use EarlyBinder 2022-09-19 11:37:27 +02:00
bors
efa717bc2d Auto merge of #101924 - jackh726:revert-static-hrtb-error, r=compiler-errors
Re-add HRTB implied static bug note

r? `@compiler-errors` since you reviewed it previously

I deleted a `normalize` call and forgot about it. Whoops.
2022-09-19 04:56:14 +00:00
mejrs
14e9893023 Print out the proper crate path 2022-09-18 02:59:32 +02:00
mejrs
3699c2497b Address feedback 2022-09-18 02:44:44 +02:00
mejrs
8477b9b707 Note if mismatched types have a similar name 2022-09-18 02:43:42 +02:00
bors
48de123d7a Auto merge of #101857 - lcnr:make-dyn-again, r=jackh726
change `FnMutDelegate` to trait objects

cc #100016 as mentioned in the last t-compiler meeting

r? `@jackh726`
2022-09-17 13:37:48 +00:00
Dylan DPC
3ad81e0dd8
Rollup merge of #93628 - est31:stabilize_let_else, r=joshtriplett
Stabilize `let else`

🎉  **Stabilizes the `let else` feature, added by [RFC 3137](https://github.com/rust-lang/rfcs/pull/3137).** 🎉

Reference PR: https://github.com/rust-lang/reference/pull/1156

closes #87335 (`let else` tracking issue)

FCP: https://github.com/rust-lang/rust/pull/93628#issuecomment-1029383585

----------

## Stabilization report

### Summary

The feature allows refutable patterns in `let` statements if the expression is
followed by a diverging `else`:

```Rust
fn get_count_item(s: &str) -> (u64, &str) {
    let mut it = s.split(' ');
    let (Some(count_str), Some(item)) = (it.next(), it.next()) else {
        panic!("Can't segment count item pair: '{s}'");
    };
    let Ok(count) = u64::from_str(count_str) else {
        panic!("Can't parse integer: '{count_str}'");
    };
    (count, item)
}
assert_eq!(get_count_item("3 chairs"), (3, "chairs"));
```

### Differences from the RFC / Desugaring

Outside of desugaring I'm not aware of any differences between the implementation and the RFC. The chosen desugaring has been changed from the RFC's [original](https://rust-lang.github.io/rfcs/3137-let-else.html#reference-level-explanations). You can read a detailed discussion of the implementation history of it in `@cormacrelf` 's [summary](https://github.com/rust-lang/rust/pull/93628#issuecomment-1041143670) in this thread, as well as the [followup](https://github.com/rust-lang/rust/pull/93628#issuecomment-1046598419). Since that followup, further changes have happened to the desugaring, in #98574, #99518, #99954. The later changes were mostly about the drop order: On match, temporaries drop in the same order as they would for a `let` declaration. On mismatch, temporaries drop before the `else` block.

### Test cases

In chronological order as they were merged.

Added by df9a2e0687 (#87688):

* [`ui/pattern/usefulness/top-level-alternation.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/pattern/usefulness/top-level-alternation.rs) to ensure the unreachable pattern lint visits patterns inside `let else`.

Added by 5b95df4bdc (#87688):

* [`ui/let-else/let-else-bool-binop-init.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-bool-binop-init.rs) to ensure that no lazy boolean expressions (using `&&` or `||`) are allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-brace-before-else.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-brace-before-else.rs) to ensure that no `}` directly preceding the `else` is allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-check.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-check.rs) to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for the `else` block.
* [`ui/let-else/let-else-irrefutable.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-irrefutable.rs) to ensure that the `irrefutable_let_patterns` lint fires.
* [`ui/let-else/let-else-missing-semicolon.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-missing-semicolon.rs) to ensure the presence of semicolons at the end of the `let` statement.
* [`ui/let-else/let-else-non-diverging.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-non-diverging.rs) to ensure the `else` block diverges.
* [`ui/let-else/let-else-run-pass.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-run-pass.rs) to ensure the feature works in some simple test case settings.
* [`ui/let-else/let-else-scope.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-scope.rs) to ensure the bindings created by the outer `let` expression are not available in the `else` block of it.

Added by bf7c32a447 (#89965):

* [`ui/let-else/issue-89960.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/issue-89960.rs) as a regression test for the ICE-on-error bug #89960 . Later in 102b9125e1 this got removed in favour of more comprehensive tests.

Added by 856541963c (#89974):

* [`ui/let-else/let-else-if.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-if.rs) to test for the improved error message that points out that `let else if` is not possible.

Added by 9b45713b6c:

* [`ui/let-else/let-else-allow-unused.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-unused.rs) as a regression test for #89807, to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for bindings created by the `let else` pattern.

Added by 61bcd8d307 (#89841):

* [`ui/let-else/let-else-non-copy.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-non-copy.rs) to ensure that a copy is performed out of non-copy wrapper types. This mirrors `if let` behaviour. The test case bases on rustc internal changes originally meant for #89933 but then removed from the PR due to the error prior to the improvements of #89841.
* [`ui/let-else/let-else-source-expr-nomove-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs) to ensure that while there is a move of the binding in the successful case, the `else` case can still access the non-matching value. This mirrors `if let` behaviour.

Added by 102b9125e1 (#89841):

* [`ui/let-else/let-else-ref-bindings.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings.rs) and [`ui/let-else/let-else-ref-bindings-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings-pass.rs) to check `ref` and `ref mut` keywords in the pattern work correctly and error when needed.

Added by 2715c5f984 (#89841):

* Match ergonomic tests adapted from the `rfc2005` test suite.

Added by fec8a507a2 (#89841):

* [`ui/let-else/let-else-deref-coercion-annotated.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion-annotated.rs) and [`ui/let-else/let-else-deref-coercion.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion.rs) to check deref coercions.

#### Added since this stabilization report was originally written (2022-02-09)

Added by 76ea566677 (#94211):

* [`ui/let-else/let-else-destructuring.rs`](https://github.com/rust-lang/rust/blob/1.63.0/src/test/ui/let-else/let-else-destructuring.rs) to give a nice error message if an user tries to do an assignment with a (possibly refutable) pattern and an `else` block, like asked for in #93995.

Added by e7730dcb7e (#94208):

* [`ui/let-else/let-else-allow-in-expr.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-in-expr.rs) to test whether `#[allow(unused_variables)]` works in the expr, as well as its non presence, as well as putting it on the entire `let else` *affects* the expr, too. This was adding a missing test as pointed out by the stabilization report.
* Expansion of `ui/let-else/let-else-allow-unused.rs` and `ui/let-else/let-else-check.rs` to ensure that non-presence of `#[allow(unused)]` does issue the unused lint. This was adding a missing test case as pointed out by the stabilization report.

Added by 5bd71063b3 (#94208):

* [`ui/let-else/let-else-slicing-error.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-slicing-error.rs), a regression test for #92069, which got fixed without addition of a regression test. This resolves a missing test as pointed out by the stabilization report.

Added by 5374688e1d (#98574):

* [`src/test/ui/async-await/async-await-let-else.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/async-await/async-await-let-else.rs) to test the interaction of async/await with `let else`

Added by 6c529ded86 (#98574):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a (partial) regression test for #98672

Added by 9b56640106 (#99518):

* [`src/test/ui/let-else/let-else-temp-borrowck.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a regression test for #93951
* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #98672 (especially regarding `else` drop order)

Added by baf9a7cb57 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #93951, similar to `let-else-temp-borrowck.rs`

Added by 60be2de8b7 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a program that can now be compiled thanks to borrow checker implications of #99518

Added by 47a7a91c96 (#100132):

* [`src/test/ui/let-else/issue-100103.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-100103.rs), as a regression test for #100103, to ensure that there is no ICE when doing `Err(...)?` inside else blocks.

Added by e3c5bd617d (#100443):

* [`src/test/ui/let-else/let-else-then-diverge.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-then-diverge.rs), to verify that there is no unreachable code error with the current desugaring.

Added by 981852677c (#100443):

* [`src/test/ui/let-else/issue-94176.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-94176.rs), to make sure that a correct span is emitted for a missing trailing expression error. Regression test for #94176.

Added by e182d12a84 (#100434):

* [src/test/ui/unpretty/pretty-let-else.rs](https://github.com/rust-lang/rust/blob/master/src/test/ui/unpretty/pretty-let-else.rs), as a regression test to ensure pretty printing works for `let else` (this bug surfaced in many different ways)

Added by e26285603c (#99954):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) extended to contain & borrows as well, as this was identified as an earlier issue with the desugaring: https://github.com/rust-lang/rust/issues/98672#issuecomment-1200196921

Added by 2d8460ef43 (#99291):

* [`src/test/ui/let-else/let-else-drop-order.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-drop-order.rs) a matrix based test for various drop order behaviour of `let else`. Especially, it verifies equality of `let` and `let else` drop orders, [resolving](https://github.com/rust-lang/rust/pull/93628#issuecomment-1238498468) a [stabilization blocker](https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523).

Added by 1b87ce0d40 (#101410):

* Edit to `src/test/ui/let-else/let-else-temporary-lifetime.rs` to add the `-Zvalidate-mir` flag, as a regression test for #99228

Added by af591ebe4d (#101410):

* [`src/test/ui/let-else/issue-99975.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-99975.rs) as a regression test for the ICE #99975.

Added by this PR:

* `ui/let-else/let-else.rs`, a simple run-pass check, similar to `ui/let-else/let-else-run-pass.rs`.

### Things not currently tested

* ~~The `#[allow(...)]` tests check whether allow works, but they don't check whether the non-presence of allow causes a lint to fire.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~There is no `#[allow(...)]` test for the expression, as there are tests for the pattern and the else block.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~`let-else-brace-before-else.rs` forbids the `let ... = {} else {}` pattern and there is a rustfix to obtain `let ... = ({}) else {}`. I'm not sure whether the `.fixed` files are checked by the tooling that they compile. But if there is no such check, it would be neat to make sure that `let ... = ({}) else {}` compiles.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~#92069 got closed as fixed, but no regression test was added. Not sure it's worth to add one.~~ → *test added by 5bd71063b3810d977aa376d1e6dd7cec359330cc*
* ~~consistency between `let else` and `if let` regarding lifetimes and drop order: https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523~~ → *test added by 2d8460ef43d902f34ba2133fe38f66ee8d2fdafc*

Edit: they are all tested now.

### Possible future work / Refutable destructuring assignments

[RFC 2909](https://rust-lang.github.io/rfcs/2909-destructuring-assignment.html) specifies destructuring assignment, allowing statements like `FooBar { a, b, c } = foo();`.
As it was stabilized, destructuring assignment only allows *irrefutable* patterns, which before the advent of `let else` were the only patterns that `let` supported.
So the combination of `let else` and destructuring assignments gives reason to think about extensions of the destructuring assignments feature that allow refutable patterns, discussed in #93995.

A naive mapping of `let else` to destructuring assignments in the form of `Some(v) = foo() else { ... };` might not be the ideal way. `let else` needs a diverging `else` clause as it introduces new bindings, while assignments have a default behaviour to fall back to if the pattern does not match, in the form of not performing the assignment. Thus, there is no good case to require divergence, or even an `else` clause at all, beyond the need for having *some* introducer syntax so that it is clear to readers that the assignment is not a given (enums and structs look similar). There are better candidates for introducer syntax however than an empty `else {}` clause, like `maybe` which could be added as a keyword on an edition boundary:

```Rust
let mut v = 0;
maybe Some(v) = foo(&v);
maybe Some(v) = foo(&v) else { bar() };
```

Further design discussion is left to an RFC, or the linked issue.
2022-09-17 15:31:06 +05:30
bors
c524c7dd25 Auto merge of #98588 - b-naber:valtrees-cleanup, r=lcnr
Use only ty::Unevaluated<'tcx, ()> in type system

r? `@lcnr`
2022-09-17 03:04:22 +00:00
Jack Huey
e09242d5b8 Final bits 2022-09-16 17:47:53 -04:00
Jack Huey
9929c0ac76 Add AscribeUserTypeProvePredicate 2022-09-16 17:20:11 -04:00
Jack Huey
67653292be Add to_constraint_category to ObligationCause and SubregionOrigin 2022-09-16 17:00:11 -04:00
Jack Huey
6075877c89 Pass ConstraintCategory thorough a few more places 2022-09-16 16:44:18 -04:00
Jack Huey
a46376e247 Make QueryOutlivesConstraint contain a ConstraintCategory 2022-09-16 16:15:41 -04:00
bors
4d4e51e428 Auto merge of #101902 - jackh726:revert-static-hrtb-error, r=nikomatsakis
Partially revert #101433

reverts #101433 to fix #101844

We should get this into the beta cut, since the ICE is getting hit quite a bit.
2022-09-16 16:46:14 +00:00
Jack Huey
92b759f517 Revert "Better errors for implied static bound"
This reverts commit c75817b0a7.
2022-09-16 09:47:07 -04:00
Deadbeef
5ead742e18 remap ParamEnv with obligation 2022-09-16 12:08:46 +08:00
est31
173eb6f407 Only enable the let_else feature on bootstrap
On later stages, the feature is already stable.

Result of running:

rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
2022-09-15 21:06:45 +02:00
Oli Scherer
8aed75bee0 Don't throw away information just to recompute it again 2022-09-15 16:23:10 +00:00
lcnr
5669ce1a28 change FnMutDelegate to trait objects 2022-09-15 16:59:58 +02:00
bors
6153d3cbe6 Auto merge of #101212 - eholk:dyn-star, r=compiler-errors
Initial implementation of dyn*

This PR adds extremely basic and incomplete support for [dyn*](https://smallcultfollowing.com/babysteps//blog/2022/03/29/dyn-can-we-make-dyn-sized/). The goal is to get something in tree behind a flag to make collaboration easier, and also to make sure the implementation so far is not unreasonable. This PR does quite a few things:

* Introduce `dyn_star` feature flag
* Adds parsing for `dyn* Trait` types
* Defines `dyn* Trait` as a sized type
* Adds support for explicit casts, like `42usize as dyn* Debug`
  * Including const evaluation of such casts
* Adds codegen for drop glue so things are cleaned up properly when a `dyn* Trait` object goes out of scope
* Adds codegen for method calls, at least for methods that take `&self`

Quite a bit is still missing, but this gives us a starting point. Note that this is never intended to become stable surface syntax for Rust, but rather `dyn*` is planned to be used as an implementation detail for async functions in dyn traits.

Joint work with `@nikomatsakis` and `@compiler-errors.`

r? `@bjorn3`
2022-09-14 18:10:51 +00:00
Dylan DPC
430123164f
Rollup merge of #101433 - jackh726:better-static-placeholder-error, r=compiler-errors
Emit a note that static bounds from HRTBs are a bug

This note isn't perfect, but opening this to either 1) land as is or 2) get some feedback on how to improve it

Let r? `@compiler-errors` and cc. `@nikomatsakis`
2022-09-14 19:26:18 +05:30
bors
a0d1df4a5d Auto merge of #101709 - nnethercote:simplify-visitors-more, r=cjgillot
Simplify visitors more

A successor to #100392.

r? `@cjgillot`
2022-09-14 05:21:14 +00:00