Commit Graph

876 Commits

Author SHA1 Message Date
b-naber
cb35a7b481 add BorrowckInferCtxt 2023-02-19 22:07:17 +00:00
Nicholas Nethercote
bcf0ec0191 Replace mk_foo calls with infer_foo where possible.
There are several `mk_foo`/`intern_foo` pairs, where the former takes an
iterator and the latter takes a slice. (This naming convention is bad,
but that's a fix for another PR.)

This commit changes several `mk_foo` occurrences into `intern_foo`,
avoiding the need for some `.iter()`/`.into_iter()` calls. Affected
cases:
- mk_type_list
- mk_tup
- mk_substs
- mk_const_list
2023-02-17 22:24:31 +11:00
Kyle Matsuda
c183110cc2 remove bound_type_of query; make type_of return EarlyBinder; change type_of in metadata 2023-02-16 17:05:56 -07:00
Kyle Matsuda
d822b97a27 change usages of type_of to bound_type_of 2023-02-16 17:01:52 -07:00
bors
9a7cc6c32f Auto merge of #108127 - matthiaskrgr:rollup-kpzfc6j, r=matthiaskrgr
Rollup of 7 pull requests

Successful merges:

 - #106347 (More accurate spans for arg removal suggestion)
 - #108057 (Prevent some attributes from being merged with others on reexports)
 - #108090 (`if $c:expr { Some($r:expr) } else { None }` =>> `$c.then(|| $r)`)
 - #108092 (note issue for feature(packed_bundled_libs))
 - #108099 (use chars instead of strings where applicable)
 - #108115 (Do not ICE on unmet trait alias bounds)
 - #108125 (Add new people to the compiletest review rotation)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2023-02-16 19:21:02 +00:00
bors
c5d1b3ea96 Auto merge of #108020 - nnethercote:opt-mk_region, r=compiler-errors
Optimize `mk_region`

PR #107869 avoiding some interning under `mk_ty` by special-casing `Ty` variants with simple (integer) bodies. This PR does something similar for regions.

r? `@compiler-errors`
2023-02-16 16:11:54 +00:00
Maybe Waffle
5bf6a46032 Replace some thens with some then_somes 2023-02-16 15:26:03 +00:00
Maybe Waffle
8751fa1a9a if $c:expr { Some($r:expr) } else { None } =>> $c.then(|| $r) 2023-02-16 15:26:00 +00:00
b-naber
758cc95763 exhaustive matching in get_ambient_variance 2023-02-15 21:13:12 +00:00
Matthias Krüger
8f65e25aec
Rollup merge of #108010 - compiler-errors:can_eq-returns-bool, r=lcnr
Make `InferCtxt::can_eq` and `InferCtxt::can_sub` return booleans

Nobody matches on the result, nor does the result return anything useful...
2023-02-15 21:30:56 +01:00
bors
2d14db321b Auto merge of #108006 - cjgillot:def-impl, r=oli-obk
Avoid accessing HIR when it can be avoided

Experiment to see if it helps some incremental cases.

Will be rebased once https://github.com/rust-lang/rust/pull/107942 gets merged.

r? `@ghost`
2023-02-15 16:14:10 +00:00
Dylan DPC
83f10ea5b7
Rollup merge of #105300 - aliemjay:member-lower, r=oli-obk
rework min_choice algorithm of member constraints

See [this comment](https://github.com/rust-lang/rust/pull/105300#issuecomment-1384312743) for the description of the new algorithm.

Fixes #63033
Fixes #104639

This uses a more general algorithm than #89056 that doesn't treat `'static` as a special case. It thus accepts more code. For example:
```rust
async fn test2<'s>(_: &'s u8, _: &'_ &'s u8, _: &'_ &'s u8) {}
```
I claim it's more correct as well because it fixes #104639.

cc ``@nikomatsakis`` ``@lqd`` ``@tmandry`` ``@eholk`` ``@chenyukang`` ``@oli-obk``

r? types
2023-02-15 12:24:53 +05:30
Nicholas Nethercote
cef9004f5a Add specialized variants of mk_region.
Much like there are specialized variants of `mk_ty`. This will enable
some optimization in the next commit.

Also rename the existing `re_error*` functions as `mk_re_error*`, for
consistency.
2023-02-15 09:02:44 +11:00
Camille GILLOT
03dff82d59 Add of_trait to DefKind::Impl. 2023-02-14 19:55:44 +00:00
Oli Scherer
936bf29d4c s/eval_usize/eval_target_usize/ for clarity 2023-02-14 08:51:19 +00:00
Michael Goulet
eb286dd070 Make can_eq and can_sub return booleans 2023-02-13 19:29:02 +00:00
Alan Egerton
ba55a453eb
Alias folding/visiting traits instead of re-export 2023-02-13 10:24:46 +00:00
b-naber
6e1d228285 only require sub type relation on field projection types 2023-02-12 23:18:15 +01:00
bors
1623ab0246 Auto merge of #107507 - BoxyUwU:deferred_projection_equality, r=lcnr
Implement `deferred_projection_equality` for erica solver

Somewhat of a revival of #96912. When relating projections now emit an `AliasEq` obligation instead of attempting to determine equality of projections that may not be as normalized as possible (i.e. because of lazy norm, or just containing inference variables that prevent us from resolving an impl). Only do this when the new solver is enabled
2023-02-11 05:46:24 +00:00
Boxy
1f89e2aef2 emit AliasEq when relating type and const aliases 2023-02-10 14:33:13 +00:00
bors
d1ac43a9b9 Auto merge of #107652 - estebank:re_error, r=oli-obk
Introduce `ReError`

CC #69314

r? `@nagisa`
2023-02-10 10:10:12 +00:00
Jack Huey
0637b6b471 Update implied_outlives_bounds to properly register implied bounds behind normalization 2023-02-09 21:08:11 -05:00
Jack Huey
1a663c0f53 Cleanup free_region_relations a bit 2023-02-09 20:38:27 -05:00
Esteban Küber
ed8651c7b8 Use 'static RegionVid for ReError 2023-02-09 10:26:50 +00:00
Esteban Küber
861f451235 Change to ReError(ErrorGuaranteed) 2023-02-09 10:26:49 +00:00
Esteban Küber
30cf7a3f51 Introduce ReError
CC #69314
2023-02-09 10:26:49 +00:00
Matthias Krüger
ec65285fdd
Rollup merge of #107780 - compiler-errors:instantiate-binder, r=lcnr
Rename `replace_bound_vars_with_*` to `instantiate_binder_with_*`

Mentioning "binder" rather than "bound vars", imo, makes it clearer that we're doing something to the binder as a whole.

Also, "instantiate" is the verb that I'm always reaching for when I'm looking for these functions, and the name that we use in the new solver anyways.

r? types
2023-02-08 18:32:44 +01:00
Michael Goulet
03a8a4ff3e Replacing bound vars is actually instantiating a binder 2023-02-07 23:13:54 +00:00
bors
3f059f6046 Auto merge of #107768 - matthiaskrgr:rollup-9u4cal4, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #107719 (Remove `arena_cache` modifier from `upstream_monomorphizations_for`)
 - #107740 (Avoid locking the global context across the `after_expansion` callback)
 - #107746 (Split fn_ctxt/adjust_fulfillment_errors from fn_ctxt/checks)
 - #107749 (allow quick-edit convenience)
 - #107750 (make more readable)
 - #107755 (remove binder from query constraints)
 - #107756 (miri: fix ICE when running out of address space)
 - #107764 (llvm-16: Use Triple.h from new header location.)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2023-02-07 20:58:20 +00:00
lcnr
a04f31dc34 remove binder from query constraints 2023-02-07 10:59:18 +01:00
Edward Shen
af5a37e844
Modify existing bounds if they exist 2023-02-06 11:26:36 -08:00
Matthias Krüger
d381eca5dc
Rollup merge of #107646 - estebank:specific-span, r=compiler-errors
Provide structured suggestion for binding needing type on E0594

Partially address #45405.
2023-02-04 20:29:06 +01:00
bors
9dee4e4c42 Auto merge of #107267 - cjgillot:keep-aggregate, r=oli-obk
Do not deaggregate MIR

This turns out to simplify a lot of things.
I haven't checked the consequences for miri yet.

cc `@JakobDegen`
r? `@oli-obk`
2023-02-04 15:17:32 +00:00
Esteban Küber
e6c56cda09 review comments 2023-02-03 23:41:39 +00:00
Esteban Küber
da1360d981 Provide structured suggestion for binding needing type on E0594
Partially address #45405.
2023-02-03 18:53:27 +00:00
Matthias Krüger
6b94f4dccc
Rollup merge of #106575 - estebank:issue-64008, r=pnkfelix
Suggest `move` in nested closure when appropriate

Fix #64008.
2023-02-03 06:30:22 +01:00
Camille GILLOT
0241c29123 Put a DefId in AggregateKind. 2023-02-02 23:09:51 +00:00
Esteban Küber
e6b84eb797 Suggest move in nested closure when appropriate
Fix #64008.
2023-02-02 16:26:01 +00:00
Matthias Krüger
3e0995a440
Rollup merge of #107532 - compiler-errors:erase-regions-in-uninhabited, r=jackh726
Erase regions before doing uninhabited check in borrowck

~Also, fingerprint query keys/values when debug assertions are enabled. This should make it easier to check for issues like this without `-Cincremental`, and make UI tests a bit cleaner.~ edit: moving that to a separate PR

Fixes #107505
2023-02-02 17:14:07 +01:00
Michael Goulet
2c23c7f0cd Erase regions before uninhabited check 2023-02-01 01:14:34 +00:00
Guillaume Gomez
53bb6322db
Rollup merge of #107467 - WaffleLapkin:uneq, r=oli-obk
Improve enum checks

Some light refactoring.
2023-01-31 23:38:52 +01:00
bors
a64ef7d07d Auto merge of #100754 - davidtwco:translation-incremental, r=compiler-errors
incremental: migrate diagnostics

- Apply the diagnostic migration lints to more functions on `Session`, namely: `span_warn`, `span_warn_with_code`, `warn` `note_without_error`, `span_note_without_error`, `struct_note_without_error`.
- Add impls of `IntoDiagnosticArg` for `std::io::Error`, `std::path::Path` and `std::path::PathBuf`.
- Migrate the `rustc_incremental` crate's diagnostics to translatable diagnostic structs.

r? `@compiler-errors`
cc #100717
2023-01-31 10:20:58 +00:00
bors
001a77fac3 Auto merge of #107197 - aliemjay:patch-2, r=jackh726
assume MIR types are fully normalized in ascribe_user_type

This FIXME was introduced in c6a17bf8bc but it should've been restricted to `ascribe_user_type_skip_wf`.
2023-01-30 19:42:49 +00:00
David Wood
2575b1abc9 session: diagnostic migration lint on more fns
Apply the diagnostic migration lint to more functions on `Session`.

Signed-off-by: David Wood <david.wood@huawei.com>
2023-01-30 17:11:35 +00:00
David Wood
f7b42102e6 errors: implement IntoDiagnosticArg for &T
Implement `IntoDiagnosticArg` for `&'a T` when `T` implements
`IntoDiagnosticArg` and `Clone`. Makes it easier to write diagnostic
structs that borrow something which implements `IntoDiagnosticArg`.

Signed-off-by: David Wood <david.wood@huawei.com>
2023-01-30 17:11:34 +00:00
Maybe Waffle
4d75f61832 Use Mutability::{is_mut, is_not} 2023-01-30 12:26:26 +00:00
bors
a29efccb1e Auto merge of #107435 - matthiaskrgr:rollup-if5h6yu, r=matthiaskrgr
Rollup of 8 pull requests

Successful merges:

 - #106618 (Disable `linux_ext` in wasm32 and fortanix rustdoc builds.)
 - #107097 (Fix def-use dominance check)
 - #107154 (library/std/sys_common: Define MIN_ALIGN for m68k-unknown-linux-gnu)
 - #107397 (Gracefully exit if --keep-stage flag is used on a clean source tree)
 - #107401 (remove the usize field from CandidateSource::AliasBound)
 - #107413 (make more pleasant to read)
 - #107422 (Also erase substs for new infcx in pin move error)
 - #107425 (Check for missing space between fat arrow and range pattern)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2023-01-29 07:01:58 +00:00
bors
3cdd0197e7 Auto merge of #106227 - bryangarza:ctfe-limit, r=oli-obk
Use stable metric for const eval limit instead of current terminator-based logic

This patch adds a `MirPass` that inserts a new MIR instruction `ConstEvalCounter` to any loops and function calls in the CFG. This instruction is used during Const Eval to count against the `const_eval_limit`, and emit the `StepLimitReached` error, replacing the current logic which uses Terminators only.

The new method of counting loops and function calls should be more stable across compiler versions (i.e., not cause crates that compiled successfully before, to no longer compile when changes to the MIR generation/optimization are made).

Also see: #103877
2023-01-29 04:11:27 +00:00
Nilstrieb
832751fe1d Also erase substs for new infcx in pin move error
The code originally correctly erased the regions of the type it passed
to the newly created infcx. But after the `fn_sig` query was made to
return an `EarlyBinder<T>`, some substs that were around were
substituted there without erasing their regions. They were then passed
into the newly cerated infcx, which caused the ICE.
2023-01-28 20:43:16 +01:00
Kyle Matsuda
4a7d0e9754 add method_substs to CallKind 2023-01-26 20:28:31 -07:00
Kyle Matsuda
a969c194d8 fix up subst_identity vs skip_binder; add some FIXMEs as identified in review 2023-01-26 20:28:31 -07:00
Kyle Matsuda
c2414dfaa4 change fn_sig query to use EarlyBinder; remove bound_fn_sig query; add EarlyBinder to fn_sig in metadata 2023-01-26 20:28:25 -07:00
Kyle Matsuda
e982971ff2 replace usages of fn_sig query with bound_fn_sig 2023-01-26 20:15:36 -07:00
Matthias Krüger
4b97f07534
Rollup merge of #106971 - oli-obk:tait_error, r=davidtwco
Handle diagnostics customization on the fluent side (for one specific diagnostic)

r? ```@davidtwco```
2023-01-26 15:02:19 +01:00
Matthias Krüger
9e3f330656
Rollup merge of #106897 - estebank:issue-99430, r=davidtwco
Tweak E0597

CC #99430
2023-01-25 22:19:52 +01:00
Matthias Krüger
f21728fee4
Rollup merge of #105345 - yanchen4791:issue-103582-fix, r=jackh726
Add hint for missing lifetime bound on trait object when type alias is used

Fix issue #103582.

The problem: When a type alias is used to specify the return type of the method in a trait impl, the suggestion for fixing the problem of "missing lifetime bound on trait object" of the trait impl will not be created. The issue caused by the code which searches for the return trait objects when constructing the hint suggestion is not able to find the trait objects since they are specified in the type alias path instead of the return path of the trait impl.

The solution: Trace the trait objects in the type alias path and provide them along with the alias span to generate the suggestion in case the type alias is used in return type of the method in the trait impl.
2023-01-25 22:19:51 +01:00
Bryan Garza
aae331d610 During MirBorrowck, ignore ConstEvalCounter 2023-01-23 23:56:22 +00:00
Bryan Garza
d3c13a0102 Revert "Move CtfeLimit to mir_const's set of passes"
This reverts commit 332542a92223b2800ed372d2d461921147f29477.
2023-01-23 23:56:22 +00:00
Bryan Garza
08de246cd7 Move CtfeLimit to mir_const's set of passes 2023-01-23 23:56:22 +00:00
Bryan Garza
360db516cc Create stable metric to measure long computation in Const Eval
This patch adds a `MirPass` that tracks the number of back-edges and
function calls in the CFG, adds a new MIR instruction to increment a
counter every time they are encountered during Const Eval, and emit a
warning if a configured limit is breached.
2023-01-23 23:56:22 +00:00
yanchen4791
62a1e76d2b Add hint for missing lifetime bound on trait object when type alias is used 2023-01-23 09:54:45 -08:00
Vincenzo Palazzo
7d2c1103d7 fix: use LocalDefId instead of HirId in trait res
use LocalDefId instead of HirId in trait resolution to simplify
the obligation clause resolution

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-23 11:42:18 +00:00
Ali MJ Al-Nasrawy
9346eb649d
assume MIR types are fully normalized 2023-01-22 16:48:58 +03:00
Samuel Moelius
12a72f0329
Update universal_regions.rs 2023-01-22 07:38:02 -05:00
bors
21f6839352 Auto merge of #106976 - tmiasko:borrowck-lazy-dominators, r=cjgillot
Lazy dominator tree construction in borrowck

Motivated by the observation that sometimes constructed dominator tree was never queried.
2023-01-21 11:02:29 +00:00
Ali MJ Al-Nasrawy
a7a842027c even more unify Projection/Opaque in outlives code 2023-01-19 15:31:53 +03:00
bors
6d46b1ec87 Auto merge of #106503 - cjgillot:remap-nofilter, r=oli-obk
Do not filter substs in `remap_generic_params_to_declaration_params`.

The relevant filtering should have been performed by borrowck.

Fixes https://github.com/rust-lang/rust/issues/105826

r? types
2023-01-18 16:37:33 +00:00
Matthias Krüger
d26e07b91a
Rollup merge of #106747 - yanchen4791:issue-105507-fix, r=estebank
Add 'static lifetime suggestion when GAT implied 'static requirement from HRTB

Fix for issue #105507

The problem:
When generic associated types (GATs) are from higher-ranked trait bounds (HRTB), they are implied 'static requirement (see
[Implied 'static requirement from higher-ranked trait bounds](https://blog.rust-lang.org/2022/10/28/gats-stabilization.html#implied-static-requirement-from-higher-ranked-trait-bounds) for more details). If the user did not explicitly specify the `'static` lifetime when using the GAT, the current error message will only point out the type `does not live long enough` where the type is used, but not where the GAT is specified and how to fix the problem.

The solution:
Add notes at the span where the problematic GATs are specified and suggestions of how to fix the problem by adding `'static` lifetime at the right spans.
2023-01-18 06:59:20 +01:00
Tomasz Miąsko
7fe68571fa Lazy dominator tree construction in borrowck
Motivated by the observation that sometimes constructed dominator tree
was never queried.
2023-01-17 22:00:41 +01:00
yanchen4791
aadd58ef7a Add 'static lifetime suggestion when GAT implied 'static requirement from HRTB 2023-01-17 11:52:45 -08:00
Matthias Krüger
68f12338af
Rollup merge of #104505 - WaffleLapkin:no-double-spaces-in-comments, r=jackh726
Remove double spaces after dots in comments

Most of the comments do not have double spaces, so I assume these are typos.
2023-01-17 20:21:25 +01:00
Ali MJ Al-Nasrawy
837c1aff05 rework min_choice algorithm of member constraints
See the inline comments for the description of the new algorithm.
2023-01-17 18:38:49 +03:00
Oli Scherer
64e5f9129f Handle diagnostics customization on the fluent side 2023-01-17 08:21:34 +00:00
Maybe Waffle
6a28fb42a8 Remove double spaces after dots in comments 2023-01-17 08:09:33 +00:00
Matthias Krüger
6b49435480
Rollup merge of #106829 - compiler-errors:more-alias-combine, r=spastorino
Unify `Opaque`/`Projection` handling in region outlives code

They share basically identical paths in most places which are even easier to unify now that they're both `ty::Alias`

r? types
2023-01-17 05:25:22 +01:00
Esteban Küber
7b8251e188 Account for method call and indexing when looking for inner-most path in expression 2023-01-17 02:52:43 +00:00
Esteban Küber
c6111e8d23 Account for field access when looking for inner-most path in expression 2023-01-17 02:47:50 +00:00
Esteban Küber
be2ec32b18 Account for * when looking for inner-most path in expression 2023-01-17 02:45:11 +00:00
Matthias Krüger
d2a8a9fb36
Rollup merge of #106940 - oli-obk:tait_error, r=compiler-errors
Improve a TAIT error and add an error code plus documentation

cc https://github.com/rust-lang/rust/issues/106858
2023-01-16 20:29:39 +01:00
Oli Scherer
6b69b5e460 Improve a TAIT error and add an error code plus documentation 2023-01-16 16:54:14 +00:00
Esteban Küber
656db98bd9 Tweak E0597
CC #99430
2023-01-15 19:46:20 +00:00
Michael Goulet
90df86f474 Remove bound_{explicit,}_item_bounds 2023-01-15 15:36:06 +00:00
Michael Goulet
9b28edb6d7 Make InstantiatedPredicates impl IntoIterator 2023-01-15 15:36:06 +00:00
André Vennberg
0e65003c9e Fix some missed double spaces. 2023-01-14 18:23:40 +01:00
André Vennberg
da3623abab Removed various double spaces in compiler source comments. 2023-01-14 17:34:59 +01:00
Michael Goulet
1ea6862db3 Unify Opaque/Projection handling in region outlives code 2023-01-13 23:53:28 +00:00
Matthias Krüger
57b371ab14
Rollup merge of #106641 - chenyukang:yukang/fix-105761-segguest-this, r=estebank
Provide help on closures capturing self causing borrow checker errors

Fixes #105761

r? ````@estebank````
2023-01-13 19:16:43 +01:00
Esteban Küber
06a2d2d001 Fix ICE formatting 2023-01-12 23:46:58 +00:00
yukang
eafbca9166 take care when there is no args in method call 2023-01-12 20:17:28 +08:00
yukang
c82545955e Provide help on closures capturing self causing borrow checker errors 2023-01-12 20:17:25 +08:00
Camille GILLOT
b7bb8a5ce9 Do not filter substs in remap_generic_params_to_declaration_params.
The relevant filtering should have been performed by borrowck.
2023-01-11 16:29:25 +00:00
Albert Larsan
40ba0e84d5
Change src/test to tests in source files, fix tidy and tests 2023-01-11 09:32:13 +00:00
Yuki Okushi
e5e116dca9
Rollup merge of #106204 - compiler-errors:no-take-opaques-in-compare, r=oli-obk
No need to take opaques in `check_type_bounds`

`InferCtxt` already has its defining use anchor set to err

r? ``@oli-obk``
2023-01-10 08:05:34 +09:00
bors
3020239de9 Auto merge of #106637 - fee1-dead-contrib:rollup-ticvmsd, r=fee1-dead
Rollup of 10 pull requests

Successful merges:

 - #105292 (Change a commit_if_ok call to probe)
 - #105655 (Remove invalid case for mutable borrow suggestion)
 - #106047 (Fix ui constant tests for big-endian platforms)
 - #106061 (Enable Shadow Call Stack for Fuchsia on AArch64)
 - #106164 (Move `check_region_obligations_and_report_errors` to `TypeErrCtxt`)
 - #106291 (Fix incorrect suggestion for extra `&` in pattern)
 - #106389 (Simplify some canonical type alias names)
 - #106468 (Use FxIndexSet when updating obligation causes in `adjust_fulfillment_errors_for_expr_obligation`)
 - #106549 (Use fmt named parameters in rustc_borrowck)
 - #106614 (error-code docs improvements (No. 2))

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2023-01-09 18:20:00 +00:00
Michael Goulet
f769d34291 Assert defining anchor is set in take_opaque_types 2023-01-09 18:14:28 +00:00
fee1-dead
99529b0cd2
Rollup merge of #106549 - wcampbell0x2a:use-fmt-named-parameters-borrowck, r=estebank
Use fmt named parameters in rustc_borrowck
2023-01-09 23:35:31 +08:00
bors
af58fc8699 Auto merge of #101947 - aliemjay:astconv-normalize, r=lcnr
Don't normalize in AstConv

See individual commits.

Fixes #101350
Fixes #54940
2023-01-09 15:29:59 +00:00
Yuki Okushi
fe075319e6
Rollup merge of #106410 - clubby789:borrow-mut-self-mut-self-diag, r=compiler-errors
Suggest `mut self: &mut Self` for `?Sized` impls

Closes #106325
Closes #93078

The suggestion is _probably_ not what the user wants (hence `MaybeIncorrect`) but at least makes the problem in the above issues clearer. It might be better to add a note explaining why this is the case, but I'm not sure how best to word that so this is a start.

``@rustbot`` label +A-diagnostics
2023-01-08 17:01:46 +09:00
Matthias Krüger
1e6710da59
Rollup merge of #106509 - estebank:closure-in-block, r=davidtwco
Detect closures assigned to binding in block

Fix #58497.
2023-01-07 20:43:22 +01:00
Ali MJ Al-Nasrawy
c6a17bf8bc make ascribe_user_type a TypeOp
Projection types in user annotations may contain inference variables.
This makes the normalization depend on the unification with the actual
type and thus requires a separate TypeOp to track the obligations.
Otherwise simply calling `TypeChecker::normalize` would ICE with
"unexpected ambiguity"
2023-01-07 13:41:41 +03:00