Commit Graph

983 Commits

Author SHA1 Message Date
lcnr
f475e880a4 InferSource::GenericArg, check for contains 2022-07-04 14:04:07 +02:00
lcnr
7952d2ed83 resolve vars in node substs 2022-07-04 13:58:29 +02:00
lcnr
eef34a648b stop suggesting things inside of macros 2022-07-04 13:58:29 +02:00
lcnr
f1836c453a update infer cost computation for types 2022-07-04 13:58:29 +02:00
lcnr
c2ed08715b remove unused function argument 2022-07-04 13:58:28 +02:00
Michael Goulet
f44ae98cee Only label place where type is needed if span is meaningful 2022-07-01 17:38:34 +00:00
Matthias Krüger
0d5636ce88
Rollup merge of #98610 - lcnr:emit_inference_failure_err-ice, r=estebank
fix `emit_inference_failure_err` ICE

fixes #98598

this fix doesn't make me too happy, but 🤷
2022-07-01 06:05:52 +02:00
Oli Scherer
84fc551664 Make evaluate_obligation not succeed unconditionally if it registered new hidden types for opaque types 2022-06-30 14:23:31 +00:00
lcnr
e043821e93 add issue number to fixme 2022-06-30 15:53:17 +02:00
Oli Scherer
ade2a96ff1 use a method instead of manually doing what its body does 2022-06-30 13:24:35 +00:00
Matthias Krüger
48170d5a1c
Rollup merge of #96727 - oli-obk:no_expect, r=lcnr
Make TAIT behave exactly like RPIT

fixes https://github.com/rust-lang/rust/issues/96552

This makes type-alias-impl-trait behave like return-position-impl-trait. Unfortunately it also causes some cases to stop compiling due to "needing type annotations" and makes panicking cause fallback for the hidden type to `()`.

All of these are addressable, but we should probably address them for RPIT and TAIT together

r? ``@lcnr``
2022-06-30 00:23:50 +02:00
Matthias Krüger
d34c4ca9be
Rollup merge of #98668 - TaKO8Ki:avoid-many-&str-to-string-conversions, r=Dylan-DPC
Avoid some `&str` to `String` conversions with `MultiSpan::push_span_label`

This patch removes some`&str` to `String` conversions with `MultiSpan::push_span_label`.
2022-06-29 20:35:07 +02:00
Dylan DPC
fcbb2e8009
Rollup merge of #98607 - compiler-errors:tuple-wrap-suggestion, r=oli-obk
Clean up arg mismatch diagnostic, generalize tuple wrap suggestion

This is based on top of #97542, so just look at the last commit which contains the relevant changes.

1. Remove `final_arg_types` which was one of the last places we were using raw (`usize`) indices instead of typed indices in the arg mismatch suggestion code.
2. Improve the tuple wrap suggestion, now we suggest things like `call(a, b, c, d)` -> `call(a, (b, c), d)` 😺
3. Folded in fix #98645
2022-06-29 17:59:36 +05:30
Takayuki Maeda
6212e6b339 avoid many &str to String conversions with MultiSpan::push_span_label 2022-06-29 21:16:43 +09:00
bors
66c83ffca1 Auto merge of #98558 - nnethercote:smallvec-1.8.1, r=lqd
Update `smallvec` to 1.8.1.

This pulls in https://github.com/servo/rust-smallvec/pull/282, which
gives some small wins for rustc.

r? `@lqd`
2022-06-29 09:11:29 +00:00
Oli Scherer
c33b127d7c The only reason we had to replace opaque types in closures was due to async fn desugaring, make that explicit 2022-06-29 08:58:36 +00:00
Oli Scherer
524d2b3178 Make RPIT and TAIT work exactly the same 2022-06-29 08:58:36 +00:00
Dylan DPC
c703d11dcc
Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, r=oli-obk
Remove a back-compat hack on lazy TAIT

This PR's motivation is here: https://github.com/rust-lang/rust/issues/72614#issuecomment-1134595446
~~But removing a hack doesn't seem to reject the code on the issue, there're some more hacks?~~
r? ``@oli-obk``
2022-06-28 15:30:00 +05:30
lcnr
1d845bd412 fix emit_inference_failure_err ICE 2022-06-28 11:44:25 +02:00
Michael Goulet
75337775f7 Remove final_arg_types, improve tuple wrapping suggestion 2022-06-28 00:19:49 -07:00
lcnr
28fafc45e6 lower-generic vs. outlive 2022-06-27 16:06:46 +02:00
lcnr
70497d9d10 fold_region: remove unused parameter 2022-06-27 15:55:03 +02:00
lcnr
4dbf9ba0ab outside of borrowck, do not provide an implicit_region_bound
see comment added to the field in `VerifyBoundCx`.
2022-06-27 15:48:54 +02:00
Yuki Okushi
c24f06354a
Remove a back-compat hack on lazy TAIT 2022-06-27 20:43:44 +09:00
Nicholas Nethercote
7c40661ddb Update smallvec to 1.8.1.
This pulls in https://github.com/servo/rust-smallvec/pull/282, which
gives some small wins for rustc.
2022-06-27 08:48:55 +10:00
Matthias Krüger
65187f51dc
Rollup merge of #98311 - eggyal:reverse-folder-hierarchy, r=jackh726
Reverse folder hierarchy

#91318 introduced a trait for infallible folders distinct from the fallible version.  For some reason (completely unfathomable to me now that I look at it with fresh eyes), the infallible trait was a supertrait of the fallible one: that is, all fallible folders were required to also be infallible.  Moreover the `Error` associated type was defined on the infallible trait!  It's so absurd that it has me questioning whether I was entirely sane.

This trait reverses the hierarchy, so that the fallible trait is a supertrait of the infallible one: all infallible folders are required to also be fallible (which is a trivial blanket implementation).  This of course makes much more sense!  It also enables the `Error` associated type to sit on the fallible trait, where it sensibly belongs.

There is one downside however: folders expose a `tcx` accessor method.  Since the blanket fallible implementation for infallible folders only has access to a generic `F: TypeFolder`, we need that trait to expose such an accessor to which we can delegate.  Alternatively it's possible to extract that accessor into a separate `HasTcx` trait (or similar) that would then be a supertrait of both the fallible and infallible folder traits: this would ensure that there's only one unambiguous `tcx` method, at the cost of a little additional boilerplate.  If desired, I can submit that as a separate PR.

r? ````@jackh726````
2022-06-25 15:14:11 +02:00
bors
d017d59ed0 Auto merge of #98109 - nikomatsakis:issue-98095, r=jackh726
fix universes in the NLL type tests

In the NLL code, we were not accommodating universes in the
`type_test` logic.

Fixes #98095.

r? `@compiler-errors`

This breaks some tests, however, so the purpose of this branch is more explanatory and perhaps to do a crater run.
2022-06-24 07:39:28 +00:00
Niko Matsakis
e93e10516e run x.py fmt 2022-06-23 17:00:46 -04:00
Niko Matsakis
9118fafd40 remove misleading comment
per aliemjay's suggestion
2022-06-23 17:00:28 -04:00
Niko Matsakis
d8337ee2f4 try to clarify confusing comment 2022-06-23 17:00:28 -04:00
Niko Matsakis
c3137d9e8c normalize if-eq bounds before testing
Hat-tip: aliemjay
2022-06-23 17:00:28 -04:00
Niko Matsakis
e6b630c5b1
apply suggestions from oli-obk
Co-authored-by: Oli Scherer <github35764891676564198441@oli-obk.de>
2022-06-23 16:40:06 -04:00
Niko Matsakis
c9bf88ccf9 coallesce docs 2022-06-23 16:38:24 -04:00
Niko Matsakis
27e0f7a886 rename IfEqBound to IfEq 2022-06-23 16:35:47 -04:00
Niko Matsakis
893b919e64 remove VerifyBound::IfEq variant 2022-06-23 16:28:46 -04:00
Yuki Okushi
dfc6d7ac76
Rollup merge of #97818 - compiler-errors:rpit-error-spanned, r=oli-obk
Point at return expression for RPIT-related error

Certainly this needs some diagnostic refining, but I wanted to show that it was possible first and foremost. Not sure if this is the right approach. Open to feedback.

Fixes #80583
2022-06-22 15:16:12 +09:00
Michael Goulet
52409c4c90 Point at return expression for RPIT-related error 2022-06-21 18:23:37 -07:00
Yuki Okushi
fdeecb2314
Rollup merge of #97867 - lcnr:lub-binder, r=oli-obk
lub: don't bail out due to empty binders

allows for the following to compile. The equivalent code using `struct Wrapper<'upper>(fn(&'upper ());` already compiles on stable.
```rust
let _: fn(&'upper ()) = match v {
    true => lt_in_fn::<'a>(),
    false => lt_in_fn::<'b>(),
};
```
see https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=7034a677190110941223cafac6632f70 for a complete example

r? ```@rust-lang/types```
2022-06-22 07:03:59 +09:00
Alan Egerton
6ac6866bec
Reverse folder hierarchy
#91318 introduced a trait for infallible folders distinct from the fallible version.  For some reason (completely unfathomable to me now that I look at it with fresh eyes), the infallible trait was a supertrait of the fallible one: that is, all fallible folders were required to also be infallible.  Moreover the `Error` associated type was defined on the infallible trait!  It's so absurd that it has me questioning whether I was entirely sane.

This trait reverses the hierarchy, so that the fallible trait is a supertrait of the infallible one: all infallible folders are required to also be fallible (which is a trivial blanket implementation).  This of course makes much more sense!  It also enables the `Error` associated type to sit on the fallible trait, where it sensibly belongs.

There is one downside however: folders expose a `tcx` accessor method.  Since the blanket fallible implementation for infallible folders only has access to a generic `F: TypeFolder`, we need that trait to expose such an accessor to which we can delegate.  Alternatively it's possible to extract that accessor into a separate `HasTcx` trait (or similar) that would then be a supertrait of both the fallible and infallible folder traits: this would ensure that there's only one unambiguous `tcx` method, at the cost of a little additional boilerplate.  If desired, I can submit that as a separate PR.

r? @jackh726
2022-06-21 17:38:22 +01:00
Oli Scherer
d2ea7e2059 Avoid an ICE and instead let the compiler report a useful error 2022-06-21 08:47:02 +00:00
Niko Matsakis
b7b3d2cee0 generalize the outlives obligation code
The code now accepts `Binder<OutlivesPredicate>`
instead of just `OutlivesPredicate` and thus exercises
the new, generalized `IfEqBound` codepaths. Note though
that we never *produce* Binder<OutlivesPredicate>, so we
are only testing a subset of those codepaths that excludes
actual higher-ranked outlives bounds.
2022-06-15 11:47:05 -04:00
Niko Matsakis
10f0f66d45 improved debug output 2022-06-15 11:47:05 -04:00
Niko Matsakis
87c2907bca remove compare-fn and use erased-ty 2022-06-15 11:47:04 -04:00
Niko Matsakis
e260afc3ba simplify argument type for to take param-ty
we don't really take other things
2022-06-15 11:47:04 -04:00
Niko Matsakis
c5ed318b22 implement (unused) matching solver 2022-06-15 11:47:04 -04:00
Niko Matsakis
d203c13db2 simply the IfEq bound -- we only ever use a region
the excessive generality becomes annoying later because
it wouldn't implement type folding etc
2022-06-15 11:47:04 -04:00
Yuki Okushi
87e373e82f
Rollup merge of #98110 - cjgillot:closure-brace, r=Aaron1011
Make `ExprKind::Closure` a struct variant.

Simple refactor since we both need it to introduce additional fields in `ExprKind::Closure`.

r? ``@Aaron1011``
2022-06-15 19:37:14 +09:00
Yuki Okushi
bb4805118a
Rollup merge of #98067 - klensy:compiler-deps2, r=Dylan-DPC
compiler: remove unused deps

Removed unused dependencies in compiler crates and moves few `libc` under `target.cfg(unix)` .
2022-06-15 12:02:02 +09:00
b-naber
705d818bd5 implement valtrees as the type-system representation for constant values 2022-06-14 16:07:11 +02:00
Dylan DPC
9e5c5c57e9
Rollup merge of #97935 - nnethercote:rename-ConstS-val-as-kind, r=lcnr
Rename the `ConstS::val` field as `kind`.

And likewise for the `Const::val` method.

Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.

The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.

r? `@BoxyUwU`
2022-06-14 10:35:29 +02:00
bors
4e02a9281d Auto merge of #98041 - jackh726:remove-regionckmode, r=oli-obk
Remove RegionckMode in favor of calling new skip_region_resolution

Simple cleanup. We can skip a bunch of stuff for places where NLL does the region checking, so skip earlier.

r? rust-lang/types
2022-06-14 05:07:11 +00:00
Nicholas Nethercote
93e4b6ef06 Rename the ConstS::val field as kind.
And likewise for the `Const::val` method.

Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.

The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.
2022-06-14 13:06:44 +10:00
klensy
4ea4e2e76d remove currently unused deps 2022-06-13 22:20:51 +03:00
Takayuki Maeda
77d6176e69 remove unnecessary to_string and String::new 2022-06-13 15:48:40 +09:00
Jack Huey
d716245aa6 Remove RegionckMode in favor of calling new skip_region_resolution 2022-06-13 01:15:04 -04:00
Dylan DPC
53090fefd1
Rollup merge of #98012 - compiler-errors:poly-trait-refs-are-traits, r=cjgillot
`ValuePairs::PolyTraitRefs` should be called "trait"s in type error diagnostics

Pretty simple, we already do this for `ValuePairs::TraitRefs`...
2022-06-12 12:14:30 +02:00
Michael Goulet
55805ab473 Make is_suggestable work on all TypeFoldable 2022-06-11 16:38:48 -07:00
Michael Goulet
9c47afe9fa Handle empty where-clause better 2022-06-11 16:27:01 -07:00
Michael Goulet
acab4464f6 ValuePairs::PolyTraitRefs should be called 'trait' 2022-06-11 16:25:35 -07:00
Camille GILLOT
3039cfeb6a Make ExprKind::Closure a struct variant. 2022-06-12 00:16:27 +02:00
Takayuki Maeda
f9a924d3c9 remove an unnecessary format macro 2022-06-11 18:35:10 +09:00
Dylan DPC
dfbedf5692
Rollup merge of #97967 - BoxyUwU:at_docs_mention_trace, r=compiler-errors
Mention `infer::Trace` methods on `infer::At` methods' docs

I missed that you could do `infcx.at(...).trace(...).eq(a, b)` when `a` and `b` dont implement `ToTrace` but does implement `Relate` these docs would have helped see that 😅
2022-06-11 07:42:16 +02:00
Dylan DPC
59c2ff532d
Rollup merge of #97703 - lcnr:post-89862, r=estebank
some additional `need_type_info.rs` cleanup

also fixes #97698, fixes #97806

cc `@estebank`
2022-06-11 07:42:13 +02:00
Ellen
9f1d3702a4 the day that i make a PR without a tidy error.. 2022-06-10 21:47:00 +01:00
Ellen
5d91e9e941 a 2022-06-10 21:26:53 +01:00
lcnr
efdf948f43 use FxHashMap instead of BTreeMap 2022-06-10 14:24:36 +02:00
lcnr
3d26f5a000 eagerly check whether we replace any bound vars 2022-06-10 10:09:50 +02:00
lcnr
e61807c6bf update higher_ranked_sub docs 2022-06-10 10:09:50 +02:00
lcnr
cc013e05b4 bound_vars -> infer: don't return lt map 2022-06-10 10:09:50 +02:00
lcnr
543ca7d9e7 replace bound vars: make caching explicit 2022-06-10 10:09:50 +02:00
lcnr
36a4490271 rewrite combine doc comment 2022-06-09 10:45:41 +02:00
lcnr
d6b28f377c add test + don't warn on Res::SelfTy 2022-06-08 18:00:08 +02:00
lcnr
c7b6e1de66 lub: don't bail out due to empty binders 2022-06-08 12:41:42 +02:00
lcnr
f8e73ede83 need_type_info: don't ICE when detected ty alias
fixes #97698
2022-06-08 10:13:02 +02:00
lcnr
2ea468e386 dedup diagnostics default params handling 2022-06-08 10:13:00 +02:00
bors
64a7aa7016 Auto merge of #97447 - nnethercote:improve-folding, r=jackh726
Folding revamp

r? `@ghost`
2022-06-08 05:36:40 +00:00
Nicholas Nethercote
90db033955 Folding revamp.
This commit makes type folding more like the way chalk does it.

Currently, `TypeFoldable` has `fold_with` and `super_fold_with` methods.
- `fold_with` is the standard entry point, and defaults to calling
  `super_fold_with`.
- `super_fold_with` does the actual work of traversing a type.
- For a few types of interest (`Ty`, `Region`, etc.) `fold_with` instead
  calls into a `TypeFolder`, which can then call back into
  `super_fold_with`.

With the new approach, `TypeFoldable` has `fold_with` and
`TypeSuperFoldable` has `super_fold_with`.
- `fold_with` is still the standard entry point, *and* it does the
  actual work of traversing a type, for all types except types of
  interest.
- `super_fold_with` is only implemented for the types of interest.

Benefits of the new model.
- I find it easier to understand. The distinction between types of
  interest and other types is clearer, and `super_fold_with` doesn't
  exist for most types.
- With the current model is easy to get confused and implement a
  `super_fold_with` method that should be left defaulted. (Some of the
  precursor commits fixed such cases.)
- With the current model it's easy to call `super_fold_with` within
  `TypeFolder` impls where `fold_with` should be called. The new
  approach makes this mistake impossible, and this commit fixes a number
  of such cases.
- It's potentially faster, because it avoids the `fold_with` ->
  `super_fold_with` call in all cases except types of interest. A lot of
  the time the compile would inline those away, but not necessarily
  always.
2022-06-08 09:24:03 +10:00
Nicholas Nethercote
7480b501b4 Avoid some unnecessary returns. 2022-06-08 09:22:23 +10:00
Nicholas Nethercote
28be201d2f Use super_visit_with in a couple of visit_binder methods.
Because it's equivalent but simpler to what's currently there.
2022-06-08 09:22:23 +10:00
bors
b17e9d76f2 Auto merge of #97081 - oli-obk:outlives_query_fast_path, r=jackh726
Re-use the type op instead of calling the implied_outlives_bounds query directly

r? `@ghost`
2022-06-07 21:44:40 +00:00
bors
bb55bd449e Auto merge of #95565 - jackh726:remove-borrowck-mode, r=nikomatsakis
Remove migrate borrowck mode

Closes #58781
Closes #43234

# Stabilization proposal

This PR proposes the stabilization of `#![feature(nll)]` and the removal of `-Z borrowck`. Current borrow checking behavior of item bodies is currently done by first infering regions *lexically* and reporting any errors during HIR type checking. If there *are* any errors, then MIR borrowck (NLL) never occurs. If there *aren't* any errors, then MIR borrowck happens and any errors there would be reported. This PR removes the lexical region check of item bodies entirely and only uses MIR borrowck. Because MIR borrowck could never *not* be run for a compiled program, this should not break any programs. It does, however, change diagnostics significantly and allows a slightly larger set of programs to compile.

Tracking issue: #43234
RFC: https://github.com/rust-lang/rfcs/blob/master/text/2094-nll.md
Version: 1.63 (2022-06-30 => beta, 2022-08-11 => stable).

## Motivation

Over time, the Rust borrow checker has become "smarter" and thus allowed more programs to compile. There have been three different implementations: AST borrowck, MIR borrowck, and polonius (well, in progress). Additionally, there is the "lexical region resolver", which (roughly) solves the constraints generated through HIR typeck. It is not a full borrow checker, but does emit some errors.

The AST borrowck was the original implementation of the borrow checker and was part of the initially stabilized Rust 1.0. In mid 2017, work began to implement the current MIR borrow checker and that effort ompleted by the end of 2017, for the most part. During 2018, efforts were made to migrate away from the AST borrow checker to the MIR borrow checker - eventually culminating into "migrate" mode - where HIR typeck with lexical region resolving following by MIR borrow checking - being active by default in the 2018 edition.

In early 2019, migrate mode was turned on by default in the 2015 edition as well, but with MIR borrowck errors emitted as warnings. By late 2019, these warnings were upgraded to full errors. This was followed by the complete removal of the AST borrow checker.

In the period since, various errors emitted by the MIR borrow checker have been improved to the point that they are mostly the same or better than those emitted by the lexical region resolver.

While there do remain some degradations in errors (tracked under the [NLL-diagnostics tag](https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3ANLL-diagnostics), those are sufficiently small and rare enough that increased flexibility of MIR borrow check-only is now a worthwhile tradeoff.

## What is stabilized

As said previously, this does not fundamentally change the landscape of accepted programs. However, there are a [few](https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3ANLL-fixed-by-NLL) cases where programs can compile under `feature(nll)`, but not otherwise.

There are two notable patterns that are "fixed" by this stabilization. First, the `scoped_threads` feature, which is a continutation of a pre-1.0 API, can sometimes emit a [weird lifetime error](https://github.com/rust-lang/rust/issues/95527) without NLL. Second, actually seen in the standard library. In the `Extend` impl for `HashMap`, there is an implied bound of `K: 'a` that is available with NLL on but not without - this is utilized in the impl.

As mentioned before, there are a large number of diagnostic differences. Most of them are better, but some are worse. None are serious or happen often enough to need to block this PR. The biggest change is the loss of error code for a number of lifetime errors in favor of more general "lifetime may not live long enough" error. While this may *seem* bad, the former error codes were just attempts to somewhat-arbitrarily bin together lifetime errors of the same type; however, on paper, they end up being roughly the same with roughly the same kinds of solutions.

## What isn't stabilized

This PR does not completely remove the lexical region resolver. In the future, it may be possible to remove that (while still keeping HIR typeck) or to remove it together with HIR typeck.

## Tests

Many test outputs get updated by this PR. However, there are number of tests specifically geared towards NLL under `src/test/ui/nll`

## History

* On 2017-07-14, [tracking issue opened](https://github.com/rust-lang/rust/issues/43234)
* On 2017-07-20, [initial empty MIR pass added](https://github.com/rust-lang/rust/pull/43271)
* On 2017-08-29, [RFC opened](https://github.com/rust-lang/rfcs/pull/2094)
* On 2017-11-16, [Integrate MIR type-checker with NLL](https://github.com/rust-lang/rust/pull/45825)
* On 2017-12-20, [NLL feature complete](https://github.com/rust-lang/rust/pull/46862)
* On 2018-07-07, [Don't run AST borrowck on mir mode](https://github.com/rust-lang/rust/pull/52083)
* On 2018-07-27, [Add migrate mode](https://github.com/rust-lang/rust/pull/52681)
* On 2019-04-22, [Enable migrate mode on 2015 edition](https://github.com/rust-lang/rust/pull/59114)
* On 2019-08-26, [Don't downgrade errors on 2015 edition](https://github.com/rust-lang/rust/pull/64221)
* On 2019-08-27, [Remove AST borrowck](https://github.com/rust-lang/rust/pull/64790)
2022-06-07 05:04:14 +00:00
Jack Huey
410dcc9674 Fully stabilize NLL 2022-06-03 17:16:41 -04:00
Maybe Waffle
afaa9854fa Replace &Vec<_>s with &[_]s 2022-06-03 20:42:42 +04:00
bors
e40d5e83dc Auto merge of #89862 - lcnr:path-generics-diagnostics, r=estebank
rewrite error handling for unresolved inference vars

Pretty much completely rewrites `fn emit_inference_failure_err`.

This new setup should hopefully be easier to extend and is already a lot better when looking for generic arguments.
Because this is a rewrite there are still some parts which are lacking, these are tracked in #94483 and will be fixed in later PRs.

r? `@estebank` `@petrochenkov`
2022-06-03 12:37:16 +00:00
Dylan DPC
5c041f98fa
Rollup merge of #97023 - cjgillot:uniform-anon, r=estebank
Diagnose anonymous lifetimes errors more uniformly between async and regular fns

Async fns and regular fns are desugared differently.  For the former, we create a generic parameter at HIR level.  For the latter, we just create an anonymous region for typeck.

I plan to migrate regular fns to the async fn desugaring.

Before that, this PR attempts to merge the diagnostics for both cases.

r? ```@estebank```
2022-06-02 11:13:22 +02:00
lcnr
681736a6b2 generic_arg_contains_target: ignore closures 2022-06-02 10:19:15 +02:00
lcnr
69d575e58d eagerly fetch the typeck_results 2022-06-02 10:19:15 +02:00
lcnr
bc0d12cc6c use verbose suggestions 2022-06-02 10:19:15 +02:00
lcnr
3fe346e7a3 add new emit_inference_failure_err 2022-06-02 10:19:15 +02:00
lcnr
721fc73208 remove the old emit_inference_failure_err 2022-06-02 10:19:15 +02:00
Dylan DPC
65bdfe3b41
Rollup merge of #97531 - compiler-errors:for-loop-pat-mismatch, r=davidtwco
Note pattern mismatch coming from `for` loop desugaring

Fixes #97163
2022-05-30 14:33:52 +02:00
Michael Goulet
2e25c2346b Note pattern mismatch coming from for-loop desugaring 2022-05-29 13:01:59 -07:00
bors
bef2b7cd1c Auto merge of #97214 - Mark-Simulacrum:stage0-bump, r=pietroalbini
Finish bumping stage0

It looks like the last time had left some remaining cfg's -- which made me think
that the stage0 bump was actually successful. This brings us to a released 1.62
beta though.

This now brings us to cfg-clean, with the exception of check-cfg-features in bootstrap;
I'd prefer to leave that for a separate PR at this time since it's likely to be more tricky.

cc https://github.com/rust-lang/rust/pull/97147#issuecomment-1132845061

r? `@pietroalbini`
2022-05-29 16:28:21 +00:00
Camille GILLOT
3162b33ce5 Handle anonymous lifetimes properly in diagnostics. 2022-05-29 12:16:09 +02:00
Camille GILLOT
da175c743c Make lifetime errors more precise in the presence of Fresh lifetimes. 2022-05-29 12:16:09 +02:00
Mark Rousskov
b454991ac4 Finish bumping stage0
It looks like the last time had left some remaining cfg's -- which made me think
that the stage0 bump was actually successful. This brings us to a released 1.62
beta though.
2022-05-27 07:36:17 -04:00
b-naber
5f65331b3e suggest constraining dyn trait in impl in NLL 2022-05-25 18:13:17 +02:00
b-naber
c1072d2a9a make TraitObject visitors public 2022-05-25 18:13:16 +02:00
Dylan DPC
f4bf64c3f0
Rollup merge of #97292 - compiler-errors:tcxify-rustc, r=davidtwco
Lifetime variance fixes for rustc

#97287 migrates rustc to a `Ty` type that is invariant over its lifetime `'tcx`, so I need to fix a bunch of places that assume that `Ty<'a>` and `Ty<'b>` can be unified by shortening both to some common lifetime.

This is doable, since many lifetimes are already `'tcx`, so all this PR does is be a bit more explicit that elided lifetimes are actually `'tcx`.

Split out from #97287 so the compiler team can review independently.
2022-05-23 15:11:04 +02:00
Michael Goulet
1784634a39 Lifetime variance fixes for rustc 2022-05-22 14:29:32 -07:00
Jack Huey
683a9c8391 Do leak check after function ptr coercion 2022-05-22 11:18:36 -04:00
Matthias Krüger
76f662c963
Rollup merge of #97109 - TaKO8Ki:fix-misleading-cannot-infer-type-for-type-parameter-error, r=oli-obk
Fix misleading `cannot infer type for type parameter` error

closes #93198
2022-05-20 19:54:39 +02:00
Takayuki Maeda
3d0f9fb544 report ambiguous type parameters when their parents are impl or fn
fix ci error

emit err for `impl_item`
2022-05-20 23:04:44 +09:00
lcnr
4fcf43f67c update comments 2022-05-20 11:49:29 +02:00
Yuki Okushi
13ee094260
Rollup merge of #97080 - lcnr:relate-sus, r=oli-obk
remove the `RelateResultCompare` trait

it's unused
2022-05-17 19:01:33 +09:00
Takayuki Maeda
910979a6d4 fix misleading cannot infer type for type parameter error 2022-05-17 17:34:58 +09:00
bors
c1d65eaa45 Auto merge of #96892 - oli-obk:🐌_obligation_cause_code_🐌, r=estebank
Clean up derived obligation creation

r? `@estebank`

working on fixing the perf regression from https://github.com/rust-lang/rust/pull/91030#issuecomment-1083360210
2022-05-17 01:46:25 +00:00
Oli Scherer
14da30e3e6 Split some logic from a loop into a separate function 2022-05-16 14:23:52 +00:00
Oli Scherer
340e708634 Some tracing cleanups 2022-05-16 14:23:15 +00:00
lcnr
0ea7301fa3 remove the RelateResultCompare trait 2022-05-16 15:41:05 +02:00
bors
2a8a0fc423 Auto merge of #96883 - jackh726:early-binder-2, r=oli-obk
Add EarlyBinder

Chalk has no concept of `Param` (e0ade19d13/chalk-ir/src/lib.rs (L579)) or `ReEarlyBound` (e0ade19d13/chalk-ir/src/lib.rs (L1308)). Everything  is just "bound" - the equivalent of rustc's late-bound. It's not completely clear yet whether to move everything to the same time of binder in rustc or add `Param` and `ReEarlyBound` in Chalk.

Either way, tracking when we have or haven't already substituted out these in rustc can be helpful.

As a first step, I'm just adding a `EarlyBinder` newtype that is required to call `subst`. I also add a couple "transparent" `bound_*` wrappers around a couple query that are often immediately substituted.

r? `@nikomatsakis`
2022-05-14 23:53:11 +00:00
Jack Huey
91afd02632 Add bound_explicit_item_bounds and bound_item_bounds 2022-05-14 10:16:49 -04:00
Jack Huey
6c05e8d009 Add bound_fn_sig 2022-05-13 18:27:40 -04:00
Jack Huey
c92248ab9f Add bound_type_of 2022-05-13 18:27:18 -04:00
Takayuki Maeda
daeec7e22d stop suggesting non-existing fully qualified paths 2022-05-11 19:18:02 +09:00
Jack Huey
319575ae8c Introduce EarlyBinder 2022-05-10 22:47:18 -04:00
Oli Scherer
05a62c5527 Remove clone_code method 2022-05-10 10:42:29 +00:00
Oli Scherer
704bbe5210 Move an extension trait method onto the type directly and reuse it 2022-05-10 09:26:09 +00:00
bors
030c886c29 Auto merge of #96155 - jackh726:param-heuristics-followup, r=estebank
Followups for method call error change

Each commit is self-contained. Fixes most of the followup reviews from that PR.

r? `@estebank`
2022-05-08 04:05:36 +00:00
bors
574830f573 Auto merge of #96094 - Elliot-Roberts:fix_doctests, r=compiler-errors
Begin fixing all the broken doctests in `compiler/`

Begins to fix #95994.
All of them pass now but 24 of them I've marked with `ignore HELP (<explanation>)` (asking for help) as I'm unsure how to get them to work / if we should leave them as they are.
There are also a few that I marked `ignore` that could maybe be made to work but seem less important.
Each `ignore` has a rough "reason" for ignoring after it parentheses, with

- `(pseudo-rust)` meaning "mostly rust-like but contains foreign syntax"
- `(illustrative)` a somewhat catchall for either a fragment of rust that doesn't stand on its own (like a lone type), or abbreviated rust with ellipses and undeclared types that would get too cluttered if made compile-worthy.
- `(not-rust)` stuff that isn't rust but benefits from the syntax highlighting, like MIR.
- `(internal)` uses `rustc_*` code which would be difficult to make work with the testing setup.

Those reason notes are a bit inconsistently applied and messy though. If that's important I can go through them again and try a more principled approach. When I run `rg '```ignore \(' .` on the repo, there look to be lots of different conventions other people have used for this sort of thing. I could try unifying them all if that would be helpful.

I'm not sure if there was a better existing way to do this but I wrote my own script to help me run all the doctests and wade through the output. If that would be useful to anyone else, I put it here: https://github.com/Elliot-Roberts/rust_doctest_fixing_tool
2022-05-07 06:30:29 +00:00
Jack Huey
62d0e4cba9 Resolve vars in note_type_err 2022-05-06 23:35:42 -04:00
Takayuki Maeda
857eb02abe suggest fully qualified path with appropriate params 2022-05-06 23:14:11 +09:00
Josh Triplett
0fc5c524f5 Stabilize bool::then_some 2022-05-04 13:22:08 +02:00
Elliot Roberts
7907385999 fix most compiler/ doctests 2022-05-02 17:40:30 -07:00
Vadim Petrochenkov
5b5964f569 rustc: Panic by default in DefIdTree::parent
Only crate root def-ids don't have a parent, and in majority of cases the argument of `DefIdTree::parent` cannot be a crate root.
So we now panic by default in `parent` and introduce a new non-panicing function `opt_parent` for cases where the argument can be a crate root.

Same applies to `local_parent`/`opt_local_parent`.
2022-05-02 01:56:50 +03:00
bors
7c4b476969 Auto merge of #96347 - estebank:issue-96292, r=compiler-errors
Erase type params when suggesting fully qualified path

When suggesting the use of a fully qualified path for a method call that
is ambiguous because it has multiple candidates, erase type params in
the resulting code, as they would result in an error when applied. We
replace them with `_` in the output to rely on inference. There might be
cases where this still produces slighlty incomplete suggestions, but it
otherwise produces many more errors in relatively common cases.

Fix #96292
2022-04-30 18:44:01 +00:00
Camille GILLOT
94449e6101 Store all generic bounds as where predicates. 2022-04-30 13:55:13 +02:00
Camille GILLOT
05b29f9a92 Inline WhereClause into Generics. 2022-04-30 13:51:49 +02:00
David Wood
73fa217bc1 errors: span_suggestion takes impl ToString
Change `span_suggestion` (and variants) to take `impl ToString` rather
than `String` for the suggested code, as this simplifies the
requirements on the diagnostic derive.

Signed-off-by: David Wood <david.wood@huawei.com>
2022-04-29 02:05:20 +01:00
Dylan DPC
cbfbc3be7d
Rollup merge of #96409 - marmeladema:fix-nll-introduce-named-lifetime-suggestion, r=jackh726
Recover suggestions to introduce named lifetime under NLL

Fixes #96157

r? ```@jackh726```

Built on top of #96385 so only the second commit is relevant
2022-04-28 20:13:01 +02:00
Dylan DPC
4c628bbb1c
Rollup merge of #96471 - BoxyUwU:let_else_considered_harmful, r=lcnr
replace let else with `?`

r? `@oli-obk`
2022-04-28 02:40:36 +02:00
marmeladema
2c94218238 Recover suggestions to introduce named lifetime under NLL 2022-04-27 22:36:40 +02:00
Ellen
f697955c1e tut tut tut 2022-04-27 08:51:33 +01:00
marmeladema
e1b074a2a8 Recover most impl Trait and dyn Trait lifetime bound suggestions under NLL 2022-04-25 09:14:44 +02:00
marmeladema
7b0db3e7c8 Improve span for consider adding an explicit lifetime bound suggestions under NLL
Because NLL borrowck is run after typeck, `in_progress_typeck_results`
was always `None` which was preventing the retrieval of the span to which
the suggestion is suppose to add the lifetime bound.

We now manually pass the `LocalDefId` owner to `construct_generic_bound_failure`
so that under NLL, we give the owner id of the current body.
2022-04-24 09:34:50 +02:00
Esteban Küber
a721383261 Provide consistent output order for suggestions 2022-04-23 17:54:11 -07:00
Esteban Küber
1e1f33f584 Use more targetted suggestion span for fully qualified path 2022-04-23 12:44:52 -07:00
Esteban Küber
acee1f47ef Erase type params when suggesting fully qualified path
When suggesting the use of a fully qualified path for a method call that
is ambiguous because it has multiple candidates, erase type params in
the resulting code, as they would result in an error when applied. We
replace them with `_` in the output to rely on inference. There might be
cases where this still produces slighlty incomplete suggestions, but it
otherwise produces many more errors in relatively common cases.

Fix #96292
2022-04-23 11:31:41 -07:00
bors
c102c5cfc6 Auto merge of #96020 - martingms:optimize-relate_substs, r=nnethercote
Micro-optimize `ty::relate::relate_substs` by avoiding `match`

Was a top-20 hot function in a callgrind profile of compiling `bitmaps-3.1.0`.

Yields some small speedups on that crate and some others according to local benching:

Benchmark | Profile | Scenario | % Change | Significance Factor?
-- | -- | -- | -- | --
bitmaps-3.1.0 | check | full | -1.88% | 9.42x
bitmaps-3.1.0 | debug | full | -1.80% | 8.99x
bitmaps-3.1.0 | opt | full | -1.70% | 8.49x
bitmaps-3.1.0 | check | incr-full | -1.54% | 7.68x
deep-vector | debug | full | 1.52% | 7.61x
bitmaps-3.1.0 | debug | incr-full | -1.45% | 7.26x
bitmaps-3.1.0 | opt | incr-full | -1.39% | 6.95x
nalgebra-0.30.1 | check | full | -0.68% | 3.42x
nalgebra-0.30.1 | debug | full | -0.64% | 3.22x
nalgebra-0.30.1 | opt | full | -0.64% | 3.20x
projection-caching | check | full | -0.61% | 3.05x
nalgebra-0.30.1 | check | incr-full | -0.56% | 2.78x
nalgebra-0.30.1 | opt | incr-full | -0.54% | 2.72x
nalgebra-0.30.1 | debug | incr-full | -0.54% | 2.69x
projection-caching | check | incr-full | -0.50% | 2.51x
tt-muncher | opt | full | -0.48% | 2.42x
projection-caching | opt | full | -0.47% | 2.37x
projection-caching | debug | full | -0.47% | 2.35x
projection-caching | opt | incr-full | -0.44% | 2.21x
projection-caching | debug | incr-full | -0.42% | 2.08x
deeply-nested-multi | check | incr-full | 0.37% | 1.87x
wf-projection-stress-65510 | opt | full | -0.37% | 1.84x
deep-vector | debug | incr-patched: add vec item | -0.32% | 1.61x
projection-caching | debug | incr-unchanged | -0.32% | 1.60x
wf-projection-stress-65510 | check | full | -0.31% | 1.55x
projection-caching | opt | incr-unchanged | -0.31% | 1.53x
wf-projection-stress-65510 | debug | incr-full | -0.30% | 1.51x
wf-projection-stress-65510 | opt | incr-full | -0.30% | 1.51x

r? `@nnethercote`
2022-04-19 10:53:53 +00:00
Martin Gammelsæter
19dedf3a4b Split relate_substs into two functions
One for the case with variances, and one without.
All callers use an explicit Option for the variable anyway.
2022-04-17 11:04:58 +02:00
Dylan DPC
a84a811943
Rollup merge of #95908 - compiler-errors:shallow_resolve_ty-inline, r=oli-obk
Inline `shallow_resolve_ty` into `ShallowResolver`

addresses fixme I found in infcx
2022-04-16 19:42:04 +02:00
bors
07bb916d44 Auto merge of #92364 - jackh726:Quantumplation/65853/param-heuristics, r=estebank
Better method call error messages

Rebase/continuation of #71827

~Based on #92360~
~Based on #93118~

There's a decent description in #71827 that I won't copy here (for now at least)

In addition to rebasing, I've tried to restore most of the original suggestions for invalid arguments. Unfortunately, this does make some of the errors a bit verbose. To fix this will require a bit of refactoring to some of the generalized error suggestion functions, and I just don't have the time to go into it right now.

I think this is in a state that the error messages are overall better than before without a reduction in the suggestions given.

~I've tried to split out some of the easier and self-contained changes into separate commits (mostly in #92360, but also one here). There might be more than can be done here, but again just lacking time.~

r? `@estebank` as the original reviewer of #71827
2022-04-16 06:55:28 +00:00
Jack Huey
b6c87c555f Implementation for 65853
This attempts to bring better error messages to invalid method calls, by applying some heuristics to identify common mistakes.

The algorithm is inspired by Levenshtein distance and longest common sub-sequence.   In essence, we treat the types of the function, and the types of the arguments you provided as two "words" and compute the edits to get from one to the other.

We then modify that algorithm to detect 4 cases:

 - A function input is missing
 - An extra argument was provided
 - The type of an argument is straight up invalid
 - Two arguments have been swapped
 - A subset of the arguments have been shuffled

(We detect the last two as separate cases so that we can detect two swaps, instead of 4 parameters permuted.)

It helps to understand this argument by paying special attention to terminology: "inputs" refers to the inputs being *expected* by the function, and "arguments" refers to what has been provided at the call site.

The basic sketch of the algorithm is as follows:

 - Construct a boolean grid, with a row for each argument, and a column for each input.  The cell [i, j] is true if the i'th argument could satisfy the j'th input.
 - If we find an argument that could satisfy no inputs, provided for an input that can't be satisfied by any other argument, we consider this an "invalid type".
 - Extra arguments are those that can't satisfy any input, provided for an input that *could* be satisfied by another argument.
 - Missing inputs are inputs that can't be satisfied by any argument, where the provided argument could satisfy another input
 - Swapped / Permuted arguments are identified with a cycle detection algorithm.

As each issue is found, we remove the relevant inputs / arguments and check for more issues.  If we find no issues, we match up any "valid" arguments, and start again.

Note that there's a lot of extra complexity:
 - We try to stay efficient on the happy path, only computing the diagonal until we find a problem, and then filling in the rest of the matrix.
 - Closure arguments are wrapped in a tuple and need to be unwrapped
 - We need to resolve closure types after the rest, to allow the most specific type constraints
 - We need to handle imported C functions that might be variadic in their inputs.

I tried to document a lot of this in comments in the code and keep the naming clear.
2022-04-16 02:26:56 -04:00
Dylan DPC
ba9c3a13ee
Rollup merge of #96026 - matthiaskrgr:clippy_compl_1304, r=Dylan-DPC
couple of clippy::complexity fixes
2022-04-15 20:50:47 +02:00
Dylan DPC
27e2d811e6
Rollup merge of #94457 - jhpratt:stabilize-derive_default_enum, r=davidtwco
Stabilize `derive_default_enum`

This stabilizes `#![feature(derive_default_enum)]`, as proposed in [RFC 3107](https://github.com/rust-lang/rfcs/pull/3107) and tracked in #87517. In short, it permits you to `#[derive(Default)]` on `enum`s, indicating what the default should be by placing a `#[default]` attribute on the desired variant (which must be a unit variant in the interest of forward compatibility).

```````@rustbot``````` label +S-waiting-on-review +T-lang
2022-04-15 20:50:43 +02:00
Matthias Krüger
7c2d57e0fa couple of clippy::complexity fixes 2022-04-13 22:51:34 +02:00
Michael Goulet
edeb826d0a Inline shallow_resolve_ty into ShallowResolver 2022-04-10 16:45:18 -07:00
bors
e980c62955 Auto merge of #95524 - oli-obk:cached_stable_hash_cleanups, r=nnethercote
Cached stable hash cleanups

r? `@nnethercote`

Add a sanity assertion in debug mode to check that the cached hashes are actually the ones we get if we compute the hash each time.

Add a new data structure that bundles all the hash-caching work to make it easier to re-use it for different interned data structures
2022-04-09 02:31:24 +00:00
Oli Scherer
25d6f8e0f6 Avoid looking at the internals of Interned directly 2022-04-08 15:57:44 +00:00
Jacob Pratt
abf2b4c04d
Stabilize derive_default_enum 2022-04-07 20:03:19 -04:00
David Wood
7f91697b50 errors: implement fallback diagnostic translation
This commit updates the signatures of all diagnostic functions to accept
types that can be converted into a `DiagnosticMessage`. This enables
existing diagnostic calls to continue to work as before and Fluent
identifiers to be provided. The `SessionDiagnostic` derive just
generates normal diagnostic calls, so these APIs had to be modified to
accept Fluent identifiers.

In addition, loading of the "fallback" Fluent bundle, which contains the
built-in English messages, has been implemented.

Each diagnostic now has "arguments" which correspond to variables in the
Fluent messages (necessary to render a Fluent message) but no API for
adding arguments has been added yet. Therefore, diagnostics (that do not
require interpolation) can be converted to use Fluent identifiers and
will be output as before.
2022-04-05 07:01:02 +01:00
David Wood
c45f29595d span: move MultiSpan
`MultiSpan` contains labels, which are more complicated with the
introduction of diagnostic translation and will use types from
`rustc_errors` - however, `rustc_errors` depends on `rustc_span` so
`rustc_span` cannot use types like `DiagnosticMessage` without
dependency cycles. Introduce a new `rustc_error_messages` crate that can
contain `DiagnosticMessage` and `MultiSpan`.

Signed-off-by: David Wood <david.wood@huawei.com>
2022-04-05 07:01:00 +01:00
Dylan DPC
1c82fac3f7
Rollup merge of #95560 - lcnr:obligation-cause, r=oli-obk
convert more `DefId`s to `LocalDefId`
2022-04-02 03:34:27 +02:00
Dylan DPC
1e43cf46bd
Rollup merge of #95559 - lcnr:inferctxt-typeck, r=oli-obk
small type system refactoring
2022-04-02 03:34:26 +02:00
lcnr
796b828371 convert more DefIds to LocalDefId 2022-04-01 13:38:43 +02:00
lcnr
c2b5a7ea52 remove unify_key::replace_if_possible 2022-04-01 12:41:46 +02:00
lcnr
18fae7b2e5 update comments 2022-04-01 12:41:46 +02:00
Matthias Krüger
94b1960535
Rollup merge of #95260 - compiler-errors:fn, r=davidtwco
Better suggestions for `Fn`-family trait selection errors

1. Suppress suggestions to add `std::ops::Fn{,Mut,Once}` bounds when a type already implements `Fn{,Mut,Once}`
2. Add a note that points out that a type does in fact implement `Fn{,Mut,Once}`, but the arguments vary (either by number or by actual arguments)
3. Add a note that points out that a type does in fact implement `Fn{,Mut,Once}`, but not the right one (e.g. implements `FnMut`, but `Fn` is required).

Fixes #95147
2022-04-01 06:59:41 +02:00
lcnr
a5c68d747e remove unused field from infcx 2022-03-31 17:14:42 +02:00
Yuri Astrakhan
a6dd658254 Addressed comments by @compiler-errors and @bjorn3 2022-03-30 17:04:46 -04:00
Yuri Astrakhan
5160f8f843 Spellchecking compiler comments
This PR cleans up the rest of the spelling mistakes in the compiler comments. This PR does not change any literal or code spelling issues.
2022-03-30 15:14:15 -04:00
bors
f132bcf3bd Auto merge of #94081 - oli-obk:lazy_tait_take_two, r=nikomatsakis
Lazy type-alias-impl-trait take two

### user visible change 1: RPIT inference from recursive call sites

Lazy TAIT has an insta-stable change. The following snippet now compiles, because opaque types can now have their hidden type set from wherever the opaque type is mentioned.

```rust
fn bar(b: bool) -> impl std::fmt::Debug {
    if b {
        return 42
    }
    let x: u32 = bar(false); // this errors on stable
    99
}
```

The return type of `bar` stays opaque, you can't do `bar(false) + 42`, you need to actually mention the hidden type.

### user visible change 2: divergence between RPIT and TAIT in return statements

Note that `return` statements and the trailing return expression are special with RPIT (but not TAIT). So

```rust
#![feature(type_alias_impl_trait)]
type Foo = impl std::fmt::Debug;

fn foo(b: bool) -> Foo {
    if b {
        return vec![42];
    }
    std::iter::empty().collect() //~ ERROR `Foo` cannot be built from an iterator
}

fn bar(b: bool) -> impl std::fmt::Debug {
    if b {
        return vec![42]
    }
    std::iter::empty().collect() // Works, magic (accidentally stabilized, not intended)
}
```

But when we are working with the return value of a recursive call, the behavior of RPIT and TAIT is the same:

```rust
type Foo = impl std::fmt::Debug;

fn foo(b: bool) -> Foo {
    if b {
        return vec![];
    }
    let mut x = foo(false);
    x = std::iter::empty().collect(); //~ ERROR `Foo` cannot be built from an iterator
    vec![]
}

fn bar(b: bool) -> impl std::fmt::Debug {
    if b {
        return vec![];
    }
    let mut x = bar(false);
    x = std::iter::empty().collect(); //~ ERROR `impl Debug` cannot be built from an iterator
    vec![]
}
```

### user visible change 3: TAIT does not merge types across branches

In contrast to RPIT, TAIT does not merge types across branches, so the following does not compile.

```rust
type Foo = impl std::fmt::Debug;

fn foo(b: bool) -> Foo {
    if b {
        vec![42_i32]
    } else {
        std::iter::empty().collect()
        //~^ ERROR `Foo` cannot be built from an iterator over elements of type `_`
    }
}
```

It is easy to support, but we should make an explicit decision to include the additional complexity in the implementation (it's not much, see a721052457cf513487fb4266e3ade65c29b272d2 which needs to be reverted to enable this).

### PR formalities

previous attempt: #92007

This PR also includes #92306 and #93783, as they were reverted along with #92007 in #93893

fixes #93411
fixes #88236
fixes #89312
fixes #87340
fixes #86800
fixes #86719
fixes #84073
fixes #83919
fixes #82139
fixes #77987
fixes #74282
fixes #67830
fixes #62742
fixes #54895
2022-03-30 05:04:45 +00:00
Oli Scherer
360edd611d Also use the RPIT back compat hack in trait projection 2022-03-28 17:09:00 +00:00
Oli Scherer
2aa49d4005 Fix mixing lazy TAIT and RPIT in their defining scopes 2022-03-28 17:02:21 +00:00
Oli Scherer
7f933de194 Merge two duplicates of the same logic into a common function 2022-03-28 16:59:11 +00:00
Oli Scherer
1163aa7e72 Remove opaque type obligation and just register opaque types as they are encountered.
This also registers obligations for the hidden type immediately.
2022-03-28 16:57:45 +00:00
Oli Scherer
86e1860495 Revert to inference variable based hidden type computation for RPIT 2022-03-28 16:53:47 +00:00
Oli Scherer
d5b6510bfb Have the spans of TAIT type conflict errors point to the actual site instead of the owning function 2022-03-28 16:30:59 +00:00
Oli Scherer
4b249b062b Remove some dead code 2022-03-28 16:30:34 +00:00
Oli Scherer
264cd05b16 Revert "Auto merge of #93893 - oli-obk:sad_revert, r=oli-obk"
This reverts commit 6499c5e7fc, reversing
changes made to 78450d2d60.
2022-03-28 16:27:14 +00:00
Michael Goulet
dd6683fcda suggest wrapping patterns with compatible enum variants 2022-03-27 16:10:02 -07:00
Esteban Kuber
f479e262d6 review comments and rebase 2022-03-27 02:40:07 +00:00
Esteban Kuber
b09420f95a Drive by: handle references in same_type_modulo_infer 2022-03-27 02:20:17 +00:00
Esteban Kuber
1c85987274 Point (again) to more expressions with their type, even if not fully resolved 2022-03-27 02:20:17 +00:00
Esteban Kuber
474626af50 Eagerly replace {integer}/{float} with i32/f64 for suggestion 2022-03-27 02:20:16 +00:00
bors
e70e211e99 Auto merge of #95082 - spastorino:overlap-inherent-impls, r=nikomatsakis
Overlap inherent impls

r? `@nikomatsakis`

Closes #94526
2022-03-25 09:09:48 +00:00
Dylan DPC
1fcb8fc3e0
Rollup merge of #95179 - b-naber:eval-in-try-unify, r=lcnr
Try to evaluate in try unify and postpone resolution of constants that contain inference variables

We want code like that in [`ui/const-generics/generic_const_exprs/eval-try-unify.rs`](https://github.com/rust-lang/rust/compare/master...b-naber:eval-in-try-unify?expand=1#diff-8027038201cf07a6c96abf3cbf0b0f4fdd8a64ce6292435f01c8ed995b87fe9b) to compile. To do that we need to try to evaluate constants in `try_unify_abstract_consts`, this requires us to be more careful about what constants we try to resolve, specifically we cannot try to resolve constants that still contain inference variables.

r? `@lcnr`
2022-03-25 01:34:30 +01:00
Santiago Pastorino
22b311bd82
Extract impl_subject_and_oglibations fn and make equate receive subjects 2022-03-24 12:44:06 -03:00
Michael Goulet
e0c8780a5b Better suggestions for Fn trait selection errors 2022-03-23 21:46:11 -07:00
Esteban Kuber
5fd37862d9 Properly track ImplObligations
Instead of probing for all possible impls that could have caused an
`ImplObligation`, keep track of its `DefId` and obligation spans for
accurate error reporting.

Follow up to #89580. Addresses #89418.

Remove some unnecessary clones.

Tweak output for auto trait impl obligations.
2022-03-24 02:08:49 +00:00
b-naber
11a70dbc8a erase region in ParamEnvAnd and make ConstUnifyCtxt private 2022-03-22 16:13:28 +01:00
b-naber
fe69a5cf0c dont canonicalize in try_unify_abstract_consts and erase regions instead 2022-03-22 15:27:20 +01:00
b-naber
8ff1edbe5e fix previous failures and address review 2022-03-22 11:35:59 +01:00
b-naber
3b9de6b087 dont try to unify unevaluated constants that contain infer vars 2022-03-21 18:47:38 +01:00
b-naber
47f78a2487 try to evaluate in try_unify 2022-03-21 18:47:23 +01:00
mark
bb8d4307eb rustc_error: make ErrorReported impossible to construct
There are a few places were we have to construct it, though, and a few
places that are more invasive to change. To do this, we create a
constructor with a long obvious name.
2022-03-16 10:35:24 -05:00
bors
012720ffb0 Auto merge of #94733 - nnethercote:fix-AdtDef-interning, r=fee1-dead
Improve `AdtDef` interning.

This commit makes `AdtDef` use `Interned`. Much of the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.

r? `@fee1-dead`
2022-03-12 07:02:05 +00:00
lcnr
c833a9b4b4 update comment 2022-03-11 09:51:42 +01:00
Nicholas Nethercote
ca5525d564 Improve AdtDef interning.
This commit makes `AdtDef` use `Interned`. Much the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.
2022-03-11 13:31:24 +11:00
bors
85ce7fdfa2 Auto merge of #94737 - lcnr:pass-stuff-by-value, r=davidtwco
add `#[rustc_pass_by_value]` to more types

the only interesting changes here should be to `TransitiveRelation`, but I believe to be highly unlikely that we will ever use a non `Copy` type with this type.
2022-03-10 00:15:39 +00:00
Dylan DPC
2b17c27626
Rollup merge of #94312 - pierwill:fix-94311-lattice-docs, r=jackh726
Edit `rustc_trait_selection::infer::lattice` docs

Closes #94311.

Removes mentions of outdated/missing type and filename (`infer.rs` and `LatticeValue`).
2022-03-09 06:38:50 +01:00
lcnr
b8135fd5c8 add #[rustc_pass_by_value] to more types 2022-03-08 15:39:52 +01:00
Matthias Krüger
939c1585a4
Rollup merge of #94555 - cuishuang:master, r=oli-obk
all: fix some typos

Signed-off-by: cuishuang <imcusg@gmail.com>
2022-03-03 20:01:48 +01:00
cuishuang
00fffdddd2 all: fix some typos
Signed-off-by: cuishuang <imcusg@gmail.com>
2022-03-03 19:47:23 +08:00
Caio
658ff942b0 8 - Make more use of let_chains 2022-03-02 16:02:37 -03:00
mark
e489a94dee rename ErrorReported -> ErrorGuaranteed 2022-03-02 09:45:25 -06:00
Fausto
270730f514 add suggestion to update trait if error is in impl 2022-03-01 13:00:02 -05:00
Fausto
abcccc9143 Suggest adding a new lifetime parameter when two elided lifetimes should match up for traits and impls.
Issue #94462
2022-02-28 18:16:19 -05:00
pierwill
a01427612c Edit rustc_trait_selection::infer::lattice docs
Remove mentions of outdated/missing type and filename (`infer.rs` and
`LatticeValue`).
2022-02-28 16:25:34 -06:00
bors
d981633ed6 Auto merge of #94290 - Mark-Simulacrum:bump-bootstrap, r=pietroalbini
Bump bootstrap to 1.60

This bumps the bootstrap compiler to 1.60 and cleans up cfgs and Span's rustc_pass_by_value (enabled by the bootstrap bump).
2022-02-25 18:34:02 +00:00
Matthias Krüger
ec4fc726b0
Rollup merge of #93845 - compiler-errors:in-band-lifetimes, r=cjgillot
Remove in band lifetimes

As discussed in t-lang backlog bonanza, the `in_band_lifetimes` FCP closed in favor for the feature not being stabilized. This PR removes `#![feature(in_band_lifetimes)]` in its entirety.

Let me know if this PR is too hasty, and if we should instead do something intermediate for deprecate the feature first.

r? `@scottmcm` (or feel free to reassign, just saw your last comment on #44524)
Closes #44524
2022-02-25 14:14:35 +01:00
Mark Rousskov
22c3a71de1 Switch bootstrap cfgs 2022-02-25 08:00:52 -05:00
Michael Goulet
9386ea9de2 Remove LifetimeDefOrigin 2022-02-24 18:50:33 -08:00
bors
d4de1f230c Auto merge of #93368 - eddyb:diagbld-guarantee, r=estebank
rustc_errors: let `DiagnosticBuilder::emit` return a "guarantee of emission".

That is, `DiagnosticBuilder` is now generic over the return type of `.emit()`, so we'll now have:
* `DiagnosticBuilder<ErrorReported>` for error (incl. fatal/bug) diagnostics
  * can only be created via a `const L: Level`-generic constructor, that limits allowed variants via a `where` clause, so not even `rustc_errors` can accidentally bypass this limitation
  * asserts `diagnostic.is_error()` on emission, just in case the construction restriction was bypassed (e.g. by replacing the whole `Diagnostic` inside `DiagnosticBuilder`)
  * `.emit()` returns `ErrorReported`, as a "proof" token that `.emit()` was called
    (though note that this isn't a real guarantee until after completing the work on
     #69426)
* `DiagnosticBuilder<()>` for everything else (warnings, notes, etc.)
  * can also be obtained from other `DiagnosticBuilder`s by calling `.forget_guarantee()`

This PR is a companion to other ongoing work, namely:
* #69426
  and it's ongoing implementation:
  #93222
  the API changes in this PR are needed to get statically-checked "only errors produce `ErrorReported` from `.emit()`", but doesn't itself provide any really strong guarantees without those other `ErrorReported` changes
* #93244
  would make the choices of API changes (esp. naming) in this PR fit better overall

In order to be able to let `.emit()` return anything trustable, several changes had to be made:
* `Diagnostic`'s `level` field is now private to `rustc_errors`, to disallow arbitrary "downgrade"s from "some kind of error" to "warning" (or anything else that doesn't cause compilation to fail)
  * it's still possible to replace the whole `Diagnostic` inside the `DiagnosticBuilder`, sadly, that's harder to fix, but it's unlikely enough that we can paper over it with asserts on `.emit()`
* `.cancel()` now consumes `DiagnosticBuilder`, preventing `.emit()` calls on a cancelled diagnostic
  * it's also now done internally, through `DiagnosticBuilder`-private state, instead of having a `Level::Cancelled` variant that can be read (or worse, written) by the user
  * this removes a hazard of calling `.cancel()` on an error then continuing to attach details to it, and even expect to be able to `.emit()` it
  * warnings were switched to *only* `can_emit_warnings` on emission (instead of pre-cancelling early)
  * `struct_dummy` was removed (as it relied on a pre-`Cancelled` `Diagnostic`)
* since `.emit()` doesn't consume the `DiagnosticBuilder` <sub>(I tried and gave up, it's much more work than this PR)</sub>,
  we have to make `.emit()` idempotent wrt the guarantees it returns
  * thankfully, `err.emit(); err.emit();` can return `ErrorReported` both times, as the second `.emit()` call has no side-effects *only* because the first one did do the appropriate emission
* `&mut Diagnostic` is now used in a lot of function signatures, which used to take `&mut DiagnosticBuilder` (in the interest of not having to make those functions generic)
  * the APIs were already mostly identical, allowing for low-effort porting to this new setup
  * only some of the suggestion methods needed some rework, to have the extra `DiagnosticBuilder` functionality on the `Diagnostic` methods themselves (that change is also present in #93259)
  * `.emit()`/`.cancel()` aren't available, but IMO calling them from an "error decorator/annotator" function isn't a good practice, and can lead to strange behavior (from the caller's perspective)
  * `.downgrade_to_delayed_bug()` was added, letting you convert any `.is_error()` diagnostic into a `delay_span_bug` one (which works because in both cases the guarantees available are the same)

This PR should ideally be reviewed commit-by-commit, since there is a lot of fallout in each.

r? `@estebank` cc `@Manishearth` `@nikomatsakis` `@mark-i-m`
2022-02-25 00:46:04 +00:00
bors
4b043faba3 Auto merge of #94131 - Mark-Simulacrum:fmt-string, r=oli-obk
Always format to internal String in FmtPrinter

This avoids monomorphizing for different parameters, decreasing generic code
instantiated downstream from rustc_middle -- locally seeing 7% unoptimized LLVM IR
line wins on rustc_borrowck, for example.

We likely can't/shouldn't get rid of the Result-ness on most functions, though some
further cleanup avoiding fmt::Error where we now know it won't occur may be possible,
though somewhat painful -- fmt::Write is a pretty annoying API to work with in practice
when you're trying to use it infallibly.
2022-02-24 17:18:07 +00:00
Eduard-Mihai Burtescu
b7e95dee65 rustc_errors: let DiagnosticBuilder::emit return a "guarantee of emission". 2022-02-23 06:38:52 +00:00
Eduard-Mihai Burtescu
0b9d70cf6d rustc_errors: take self by value in DiagnosticBuilder::cancel. 2022-02-23 06:08:06 +00:00
Eduard-Mihai Burtescu
8562d6b752 rustc_errors: remove struct_dummy. 2022-02-23 05:38:24 +00:00
Eduard-Mihai Burtescu
02ff9e0aef Replace &mut DiagnosticBuilder, in signatures, with &mut Diagnostic. 2022-02-23 05:38:19 +00:00
bors
b8967b0d52 Auto merge of #94225 - matthiaskrgr:rollup-0728x8n, r=matthiaskrgr
Rollup of 10 pull requests

Successful merges:

 - #91192 (Some improvements to the async docs)
 - #94143 (rustc_const_eval: adopt let else in more places)
 - #94156 (Gracefully handle non-UTF-8 string slices when pretty printing)
 - #94186 (Update pin_static_ref stabilization version.)
 - #94189 (Implement LowerHex on Scalar to clean up their display in rustdoc)
 - #94190 (Use Metadata::modified instead of FileTime::from_last_modification_ti…)
 - #94203 (CTFE engine: Scalar: expose size-generic to_(u)int methods)
 - #94211 (Better error if the user tries to do assignment ... else)
 - #94215 (trait system: comments and small nonfunctional changes)
 - #94220 (Correctly handle miniz_oxide extern crate declaration)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-02-21 22:53:45 +00:00
lcnr
6a1f5eab83 obligation forest docs 2022-02-21 12:00:26 +01:00
lcnr
239f33ea5b add comment 2022-02-21 11:02:52 +01:00
lcnr
1245131a11 use List<Ty<'tcx>> for tuples 2022-02-21 07:09:11 +01:00
Mark Rousskov
efb99d780d Always format to internal String in FmtPrinter
This avoids monomorphizing for different parameters, decreasing generic code
instantiated downstream from rustc_middle.
2022-02-20 19:32:18 -05:00
Matthias Krüger
f2d6770f77
Rollup merge of #94146 - est31:let_else, r=cjgillot
Adopt let else in more places

Continuation of #89933, #91018, #91481, #93046, #93590, #94011.

I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This is the biggest of these PRs and handles the changes outside of rustdoc, rustc_typeck, rustc_const_eval, rustc_trait_selection, which were handled in PRs #94139, #94142, #94143, #94144.
2022-02-20 00:37:34 +01:00
est31
2ef8af6619 Adopt let else in more places 2022-02-19 17:27:43 +01:00
Matthias Krüger
78e4456e1f
Rollup merge of #93990 - lcnr:pre-89862-cleanup, r=estebank
pre #89862 cleanup

changes used in #89862 which can be landed without the rest of this PR being finished.

r? `@estebank`
2022-02-19 06:45:31 +01:00
Matthias Krüger
1e2f63de0a
Rollup merge of #93892 - compiler-errors:issue-92917, r=jackh726,nikomatsakis
Only mark projection as ambiguous if GAT substs are constrained

A slightly more targeted version of #92917, where we only give up with ambiguity if we infer something about the GATs substs when probing for a projection candidate.

fixes #93874
also note (but like the previous PR, does not fix) #91762

r? `@jackh726`
cc `@nikomatsakis` who reviewed #92917
2022-02-18 23:23:09 +01:00
Matthias Krüger
dd111262b2
Rollup merge of #92683 - jackh726:issue-92033, r=estebank
Suggest copying trait associated type bounds on lifetime error

Closes #92033

Kind of the most simple suggestion to make - we don't try to be fancy. Turns out, it's still pretty useful (the couple existing tests that trigger this error end up fixed - for this error - upon applying the fix).

r? ``@estebank``
cc ``@nikomatsakis``
2022-02-18 16:23:28 +01:00
bors
feac2ecf1c Auto merge of #94088 - oli-obk:revert, r=jackh726
Revert #91403

fixes #94004

r? `@pnkfelix` `@cjgillot`
2022-02-18 07:35:37 +00:00
Matthias Krüger
637d8b89e8
Rollup merge of #94011 - est31:let_else, r=lcnr
Even more let_else adoptions

Continuation of #89933, #91018, #91481, #93046, #93590.
2022-02-17 23:00:59 +01:00
Jack Huey
3d19c8defd Suggest copying trait associated type bounds on lifetime error 2022-02-17 14:09:21 -05:00
Oli Scherer
86d17b98f2 Revert "Auto merge of #91403 - cjgillot:inherit-async, r=oli-obk"
This reverts commit 3cfa4def7c, reversing
changes made to 5d8767cb22.
2022-02-17 16:00:04 +00:00
est31
60f969a4f2 Adopt let_else in even more places 2022-02-16 22:43:39 +01:00
lcnr
1b7c3bcef9 allow special behavior when printing const infer 2022-02-16 13:37:56 +01:00
Tomasz Miąsko
cd37638c14 Inline UnifyKey::index and UnifyKey::from_index 2022-02-15 19:07:06 +01:00
Nicholas Nethercote
a95fb8b150 Overhaul Const.
Specifically, rename the `Const` struct as `ConstS` and re-introduce `Const` as
this:
```
pub struct Const<'tcx>(&'tcx Interned<ConstS>);
```
This now matches `Ty` and `Predicate` more closely, including using
pointer-based `eq` and `hash`.

Notable changes:
- `mk_const` now takes a `ConstS`.
- `Const` was copy, despite being 48 bytes. Now `ConstS` is not, so need a
  we need separate arena for it, because we can't use the `Dropless` one any
  more.
- Many `&'tcx Const<'tcx>`/`&Const<'tcx>` to `Const<'tcx>` changes
- Many `ct.ty` to `ct.ty()` and `ct.val` to `ct.val()` changes.
- Lots of tedious sigil fiddling.
2022-02-15 16:19:59 +11:00
Nicholas Nethercote
7eb15509ce Remove unnecessary RegionKind:: quals.
The variant names are exported, so we can use them directly (possibly
with a `ty::` qualifier). Lots of places already do this, this commit
just increases consistency.
2022-02-15 16:14:24 +11:00
Nicholas Nethercote
7024dc523a Overhaul RegionKind and Region.
Specifically, change `Region` from this:
```
pub type Region<'tcx> = &'tcx RegionKind;
```
to this:
```
pub struct Region<'tcx>(&'tcx Interned<RegionKind>);
```

This now matches `Ty` and `Predicate` more closely.

Things to note
- Regions have always been interned, but we haven't been using pointer-based
  `Eq` and `Hash`. This is now happening.
- I chose to impl `Deref` for `Region` because it makes pattern matching a lot
  nicer, and `Region` can be viewed as just a smart wrapper for `RegionKind`.
- Various methods are moved from `RegionKind` to `Region`.
- There is a lot of tedious sigil changes.
- A couple of types like `HighlightBuilder`, `RegionHighlightMode` now have a
  `'tcx` lifetime because they hold a `Ty<'tcx>`, so they can call `mk_region`.
- A couple of test outputs change slightly, I'm not sure why, but the new
  outputs are a little better.
2022-02-15 16:08:52 +11:00
Nicholas Nethercote
e9a0c429c5 Overhaul TyS and Ty.
Specifically, change `Ty` from this:
```
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
```
to this
```
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
```
There are two benefits to this.
- It's now a first class type, so we can define methods on it. This
  means we can move a lot of methods away from `TyS`, leaving `TyS` as a
  barely-used type, which is appropriate given that it's not meant to
  be used directly.
- The uniqueness requirement is now explicit, via the `Interned` type.
  E.g. the pointer-based `Eq` and `Hash` comes from `Interned`, rather
  than via `TyS`, which wasn't obvious at all.

Much of this commit is boring churn. The interesting changes are in
these files:
- compiler/rustc_middle/src/arena.rs
- compiler/rustc_middle/src/mir/visit.rs
- compiler/rustc_middle/src/ty/context.rs
- compiler/rustc_middle/src/ty/mod.rs

Specifically:
- Most mentions of `TyS` are removed. It's very much a dumb struct now;
  `Ty` has all the smarts.
- `TyS` now has `crate` visibility instead of `pub`.
- `TyS::make_for_test` is removed in favour of the static `BOOL_TY`,
  which just works better with the new structure.
- The `Eq`/`Ord`/`Hash` impls are removed from `TyS`. `Interned`s impls
  of `Eq`/`Hash` now suffice. `Ord` is now partly on `Interned`
  (pointer-based, for the `Equal` case) and partly on `TyS`
  (contents-based, for the other cases).
- There are many tedious sigil adjustments, i.e. adding or removing `*`
  or `&`. They seem to be unavoidable.
2022-02-15 16:03:24 +11:00
Santiago Pastorino
3c7fa0bcf3
reveal_defining_opaque_types field doesn't exist after rebase 2022-02-14 13:02:22 -03:00
Santiago Pastorino
f4bb4500dd
Call the method fork instead of clone and add proper comments 2022-02-14 12:57:20 -03:00
bors
b321742c6c Auto merge of #93938 - BoxyUwU:fix_res_self_ty, r=lcnr
Make `Res::SelfTy` a struct variant and update docs

I found pattern matching on a `(Option<DefId>, Option<(DefId, bool)>)` to not be super readable, additionally the doc comments on the types in a tuple variant aren't visible anywhere at use sites as far as I can tell (using rust analyzer + vscode)

The docs incorrectly assumed that the `DefId` in `Option<(DefId, bool)>` would only ever be for an impl item and I also found the code examples to be somewhat unclear about which `DefId` was being talked about.

r? `@lcnr` since you reviewed the last PR changing these docs
2022-02-14 12:26:43 +00:00
Matthias Krüger
aff74a1697
Rollup merge of #93810 - matthewjasper:chalk-and-canonical-universes, r=jackh726
Improve chalk integration

- Support subtype bounds in chalk lowering
- Handle universes in canonicalization
- Handle type parameters in chalk responses
- Use `chalk_ir::LifetimeData::Empty` for `ty::ReEmpty`
- Remove `ignore-compare-mode-chalk` for tests that no longer hang (they may still fail or ICE)

This is enough to get a hello world program to compile with `-Zchalk` now. Some of the remaining issues that are needed to get Chalk integration working on larger programs are:

- rust-lang/chalk#234
- rust-lang/chalk#548
- rust-lang/chalk#734
- Generators are handled differently in chalk and rustc

r? `@jackh726`
2022-02-13 06:44:14 +01:00
Matthew Jasper
030c50824c Address review comment
canonicalize_chalk_query -> canonicalize_query_preserving_universes
2022-02-12 13:39:52 +00:00
Ellen
e81e09a24e change to a struct variant 2022-02-12 11:23:53 +00:00
Camille GILLOT
a4da6308b7 Inherit lifetimes for async fn instead of duplicating them. 2022-02-12 01:26:11 +01:00
Matthew Jasper
caa10dc572 Renumber universes when canonicalizing for Chalk
This is required to avoid creating large numbers of universes from each
Chalk query, while still having enough universe information for lifetime
errors.
2022-02-11 21:38:17 +00:00
bors
6499c5e7fc Auto merge of #93893 - oli-obk:sad_revert, r=oli-obk
Revert lazy TAIT PR

Revert https://github.com/rust-lang/rust/pull/92306 (sorry `@Aaron1011,` will include your changes in the fix PR)
Revert https://github.com/rust-lang/rust/pull/93783
Revert https://github.com/rust-lang/rust/pull/92007

fixes https://github.com/rust-lang/rust/issues/93788
fixes https://github.com/rust-lang/rust/issues/93794
fixes https://github.com/rust-lang/rust/issues/93821
fixes https://github.com/rust-lang/rust/issues/93831
fixes https://github.com/rust-lang/rust/issues/93841
2022-02-11 17:39:34 +00:00
Oli Scherer
d54195db22 Revert "Auto merge of #92007 - oli-obk:lazy_tait2, r=nikomatsakis"
This reverts commit e7cc3bddbe, reversing
changes made to 734368a200.
2022-02-11 07:18:06 +00:00
Oli Scherer
2d8b8f3593 Revert "Auto merge of #92306 - Aaron1011:opaque-type-op, r=oli-obk"
This reverts commit 1f0a96862a, reversing
changes made to bf242bb119.
2022-02-11 07:17:16 +00:00
Michael Goulet
784c7a6cad only mark projection as ambiguous if GAT substs are constrained 2022-02-10 22:55:00 -08:00
Frank Steffahn
7eff2feb62 Remove further usage of &hir::Map 2022-02-10 13:04:59 +01:00
bors
1f0a96862a Auto merge of #92306 - Aaron1011:opaque-type-op, r=oli-obk
Improve opaque type higher-ranked region error message under NLL

Currently, any higher-ranked region errors involving opaque types
fall back to a generic "higher-ranked subtype error" message when
run under NLL. This PR adds better error message handling for this
case, giving us the same kinds of error messages that we currently
get without NLL:

```
error: implementation of `MyTrait` is not general enough
  --> $DIR/opaque-hrtb.rs:12:13
   |
LL | fn foo() -> impl for<'a> MyTrait<&'a str> {
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `MyTrait` is not general enough
   |
   = note: `impl MyTrait<&'2 str>` must implement `MyTrait<&'1 str>`, for any lifetime `'1`...
   = note: ...but it actually implements `MyTrait<&'2 str>`, for some specific lifetime `'2`

error: aborting due to previous error
```

To accomplish this, several different refactoring needed to be made:

* We now have a dedicated `InstantiateOpaqueType` struct which
implements `TypeOp`. This is used to invoke `instantiate_opaque_types`
during MIR type checking.
* `TypeOp` is refactored to pass around a `MirBorrowckCtxt`, which is
needed to report opaque type region errors.
* We no longer assume that all `TypeOp`s correspond to canonicalized
queries. This allows us to properly handle opaque type instantiation
(which does not occur in a query) as a `TypeOp`.
A new `ErrorInfo` associated type is used to determine what
additional information is used during higher-ranked region error
handling.
* The body of `try_extract_error_from_fulfill_cx`
has been moved out to a new function `try_extract_error_from_region_constraints`.
This allows us to re-use the same error reporting code between
canonicalized queries (which can extract region constraints directly
from a fresh `InferCtxt`) and opaque type handling (which needs to take
region constraints from the pre-existing `InferCtxt` that we use
throughout MIR borrow checking).
2022-02-09 09:41:48 +00:00
Aaron Hill
48a48fd1b8
Improve opaque type higher-ranked region error message under NLL
Currently, any higher-ranked region errors involving opaque types
fall back to a generic "higher-ranked subtype error" message when
run under NLL. This PR adds better error message handling for this
case, giving us the same kinds of error messages that we currently
get without NLL:

```
error: implementation of `MyTrait` is not general enough
  --> $DIR/opaque-hrtb.rs:12:13
   |
LL | fn foo() -> impl for<'a> MyTrait<&'a str> {
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `MyTrait` is not general enough
   |
   = note: `impl MyTrait<&'2 str>` must implement `MyTrait<&'1 str>`, for any lifetime `'1`...
   = note: ...but it actually implements `MyTrait<&'2 str>`, for some specific lifetime `'2`

error: aborting due to previous error
```

To accomplish this, several different refactoring needed to be made:

* We now have a dedicated `InstantiateOpaqueType` struct which
implements `TypeOp`. This is used to invoke `instantiate_opaque_types`
during MIR type checking.
* `TypeOp` is refactored to pass around a `MirBorrowckCtxt`, which is
needed to report opaque type region errors.
* We no longer assume that all `TypeOp`s correspond to canonicalized
queries. This allows us to properly handle opaque type instantiation
(which does not occur in a query) as a `TypeOp`.
A new `ErrorInfo` associated type is used to determine what
additional information is used during higher-ranked region error
handling.
* The body of `try_extract_error_from_fulfill_cx`
has been moved out to a new function `try_extract_error_from_region_constraints`.
This allows us to re-use the same error reporting code between
canonicalized queries (which can extract region constraints directly
from a fresh `InferCtxt`) and opaque type handling (which needs to take
region constraints from the pre-existing `InferCtxt` that we use
throughout MIR borrow checking).
2022-02-08 12:35:42 -05:00
Matthias Krüger
8429dcdb79
Rollup merge of #92715 - chordtoll:empty-string, r=davidtwco
Do not suggest char literal for zero-length strings

PR #92507 adds a hint to switch to single quotes when a char is expected and a single-character string literal is provided.

The check to ensure the string literal is one character long missed the 0-char case, and would incorrectly offer the hint.

This PR adds the missing check, and a test case to confirm the new behavior.
2022-02-08 16:40:47 +01:00
Matthias Krüger
25ce315c76
Rollup merge of #93728 - JulianKnodt:toterm, r=oli-obk
Add in ValuePair::Term

This adds in an enum when matching on positions which can either be types or consts.
It will default to emitting old special cased error messages for types.

r? `@oli-obk`
cc `@matthiaskrgr`
Fixes #93578
2022-02-08 06:47:38 +01:00
bors
e7cc3bddbe Auto merge of #92007 - oli-obk:lazy_tait2, r=nikomatsakis
Lazy type-alias-impl-trait

Previously opaque types were processed by

1. replacing all mentions of them with inference variables
2. memorizing these inference variables in a side-table
3. at the end of typeck, resolve the inference variables in the side table and use the resolved type as the hidden type of the opaque type

This worked okayish for `impl Trait` in return position, but required lots of roundabout type inference hacks and processing.

This PR instead stops this process of replacing opaque types with inference variables, and just keeps the opaque types around.
Whenever an opaque type `O` is compared with another type `T`, we make the comparison succeed and record `T` as the hidden type. If `O` is compared to `U` while there is a recorded hidden type for it, we grab the recorded type (`T`) and compare that against `U`. This makes implementing

* https://github.com/rust-lang/rfcs/pull/2515

much simpler (previous attempts on the inference based scheme were very prone to ICEs and general misbehaviour that was not explainable except by random implementation defined oddities).

r? `@nikomatsakis`

fixes #93411
fixes #88236
2022-02-07 23:40:26 +00:00
kadmin
be236d7fc2 Rm ValuePairs::Ty/Const
Remove old value pairs which is a strict subset of Terms.
2022-02-07 16:42:37 +00:00
Mara Bos
557d300e1b
Rollup merge of #91530 - bobrippling:suggest-1-tuple-parens, r=camelid
Suggest 1-tuple parentheses on exprs without existing parens

A follow-on from #86116, split out from #90677.

This alters the suggestion to add a trailing comma to create a 1-tuple - previously we would only apply this if the relevant expression was parenthesised. We now make the suggestion regardless of parentheses, which reduces the fragility of the check (w.r.t formatting).

e.g.
```rust
let a: Option<(i32,)> = Some(3);
```

gets the below suggestion:

```rust
let a: Option<(i32,)> = Some((3,));
//                           ^ ^^
```

This change also improves the suggestion in other ways, such as by only making the suggestion if the types would match after the suggestion is applied and making the suggestion a multipart suggestion.
2022-02-07 14:08:31 +00:00