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Author SHA1 Message Date
Esteban Kuber
ef212e7fb3 Point at overlapping impls when type annotations are needed 2021-10-24 18:33:04 +00:00
bors
aa5740c715 Auto merge of #90104 - spastorino:coherence-for-negative-trait, r=nikomatsakis
Implement coherence checks for negative trait impls

The main purpose of this PR is to be able to [move Error trait to core](https://github.com/rust-lang/project-error-handling/issues/3).

This feature is necessary to handle the following from impl on box.

```rust
impl From<&str> for Box<dyn Error> { ... }
```

Without having negative traits affect coherence moving the error trait into `core` and moving that `From` impl to `alloc` will cause the from impl to no longer compiler because of a potential future incompatibility. The compiler indicates that `&str` _could_ introduce an `Error` impl in the future, and thus prevents the `From` impl in `alloc` that would cause overlap with `From<E: Error> for Box<dyn Error>`. Adding `impl !Error for &str {}` with the negative trait coherence feature will disable this error by encoding a stability guarantee that `&str` will never implement `Error`, making the `From` impl compile.

We would have this in `alloc`:

```rust
impl From<&str> for Box<dyn Error> {} // A
impl<E> From<E> for Box<dyn Error> where E: Error {} // B
```

and this in `core`:

```rust
trait Error {}
impl !Error for &str {}
```

r? `@nikomatsakis`

This PR was built on top of `@yaahc` PR #85764.

Language team proposal: to https://github.com/rust-lang/lang-team/issues/96
2021-10-23 12:51:15 +00:00
Santiago Pastorino
3287f72d39
Avoid code duplication by extracting checks into fns 2021-10-23 08:55:48 -03:00
Santiago Pastorino
9534186857
Hide negative coherence checks under negative_impls feature flag 2021-10-22 17:54:20 -03:00
Santiago Pastorino
132409f0c6
Assemple trait alias candidates for negative polarity
This doesn't work properly yet, we would probably need to implement an
`assembly_neg_candidates` and consider things like `T: !AB` as `T: !A`
|| `T: !B`
2021-10-22 15:49:54 -03:00
Santiago Pastorino
da79fa964c
Add rustc_strict_coherence attribute and use it to check overlap 2021-10-22 15:49:46 -03:00
Santiago Pastorino
74454c4888
Add comment about the only way to prove NotImplemented here 2021-10-22 11:04:30 -03:00
Santiago Pastorino
2e9fb8b68b
Fix filter_impls comment 2021-10-22 10:58:38 -03:00
Santiago Pastorino
b03a0df737
Fix debug method name 2021-10-22 10:57:10 -03:00
Santiago Pastorino
5b5a2e600e
Move const filter to filter_impls 2021-10-22 10:56:32 -03:00
Santiago Pastorino
7829d9dde3
Document overlap check filter 2021-10-22 09:22:19 -03:00
Yuki Okushi
9ed9025ea9
Rollup merge of #90028 - tmiasko:structural-match-closure, r=spastorino
Reject closures in patterns

Fixes #90013.
2021-10-22 19:42:48 +09:00
Yuki Okushi
6f0acbcbd0
Rollup merge of #88644 - eopb:abstractconst_leaf_subst, r=lcnr
`AbstractConst` private fields

Calls `subst` in `AbstractConst::root` when `Node` is `Leaf`.

r? ``@lcnr``
2021-10-21 14:11:03 +09:00
Santiago Pastorino
5a727538f8
Fix allow_negative_impls logic 2021-10-20 18:05:06 -03:00
Santiago Pastorino
68d444ffa1
Add TraitObligation::polarity() for better encapsulation 2021-10-20 14:45:10 -03:00
Santiago Pastorino
7568632513
Filter candidates when goal and impl polarity doesn't match 2021-10-20 12:10:46 -03:00
Santiago Pastorino
6ae1d68e16
Use predicate_must_hold_modulo_regions 2021-10-20 12:10:46 -03:00
Santiago Pastorino
89a419cf7d
Filter out Negative impls on intercrate mode's ambiguous reasoning 2021-10-20 12:10:46 -03:00
Santiago Pastorino
85c8fd9c94
Make EvaluationCache consider polarity as cache's key 2021-10-20 12:10:46 -03:00
Santiago Pastorino
da8873e343
Only assemble_candidates_from_impls for polarity Negative 2021-10-20 12:10:46 -03:00
Santiago Pastorino
ab17068662
Consider negative polarity on trait selection 2021-10-20 12:10:45 -03:00
Santiago Pastorino
8b0bfb0dcb
Consider negative polarity on overlap check 2021-10-20 12:10:45 -03:00
Santiago Pastorino
6975afd141
Add polarity to TraitPredicate 2021-10-20 12:10:41 -03:00
Ethan Brierley
be30e60296 remove duplicate subst 2021-10-20 10:21:06 +01:00
Ethan Brierley
99b8c016ce Address lcnr review 2021-10-19 22:18:13 +01:00
Tomasz Miąsko
c97cf7fed7 Reject closures in patterns 2021-10-19 20:45:43 +02:00
bors
1af55d19c7 Auto merge of #89933 - est31:let_else, r=michaelwoerister
Adopt let_else across the compiler

This performs a substitution of code following the pattern:

```
let <id> = if let <pat> = ... { identity } else { ... : ! };
```

To simplify it to:

```
let <pat> = ... { identity } else { ... : ! };
```

By adopting the `let_else` feature (cc #87335).

The PR also updates the syn crate because the currently used version of the crate doesn't support `let_else` syntax yet.

Note: Generally I'm the person who *removes* usages of unstable features from the compiler, not adds more usages of them, but in this instance I think it hopefully helps the feature get stabilized sooner and in a better state. I have written a [comment](https://github.com/rust-lang/rust/issues/87335#issuecomment-944846205) on the tracking issue about my experience and what I feel could be improved before stabilization of `let_else`.
2021-10-19 14:41:39 +00:00
bors
ec724ac075 Auto merge of #89229 - oli-obk:i_love_inferctxt, r=jackh726
Remove redundant member-constraint check

impl trait will, for each lifetime in the hidden type, register a "member constraint" that says the lifetime must be equal or outlive one of the lifetimes of the impl trait. These member constraints will be solved by borrowck

But, as you can see in the big red block of removed code, there was an ad-hoc check for member constraints happening at the site where they get registered. This check had some minor effects on diagnostics, but will fall down on its feet with my big type alias impl trait refactor. So we removed it and I pulled the removal out into a (hopefully) reviewable PR that works on master directly.
2021-10-18 23:02:53 +00:00
Oli Scherer
4413f8c709 Member constraints already covered all of E0482 already, so that error never occurred anymore 2021-10-18 15:50:56 +00:00
Oli Scherer
2220fafa8c Guarding a loop with a check that it never runs is useless 2021-10-18 15:50:56 +00:00
est31
1418df5888 Adopt let_else across the compiler
This performs a substitution of code following the pattern:

let <id> = if let <pat> = ... { identity } else { ... : ! };

To simplify it to:

let <pat> = ... { identity } else { ... : ! };

By adopting the let_else feature.
2021-10-16 07:18:05 +02:00
Oli Scherer
16868d9096 Remove a now-unused struct 2021-10-15 17:50:33 +00:00
Niko Matsakis
094a9c743e simplify constrain_opaque_types 2021-10-15 17:50:33 +00:00
jackh726
2b5b456e23 Move some outlives bounds things from rustc_trait_selection to rustc_typeck 2021-10-15 12:14:19 -04:00
Matthias Krüger
29081f95e9
Rollup merge of #89823 - jackh726:project-overflow, r=oli-obk
Switch order of terms to prevent overflow

Fixes #89639

r? ``@pnkfelix``
2021-10-14 16:06:45 +02:00
bors
c34ac8747c Auto merge of #89247 - fee1-dead:const-eval-select, r=oli-obk
Add `const_eval_select` intrinsic

Adds an intrinsic that calls a given function when evaluated at compiler time, but generates a call to another function when called at runtime.

See https://github.com/rust-lang/const-eval/issues/7 for previous discussion.

r? `@oli-obk.`
2021-10-14 10:06:30 +00:00
jackh726
9855e7dc7b Switch order of terms to prevent overflow 2021-10-12 11:14:31 -04:00
Deadbeef
5387b6542f
Add const_eval_select intrinsic 2021-10-12 05:42:23 +00:00
Gary Guo
148f456cc6 Fix ICE 89775 2021-10-11 20:52:36 +01:00
John Kugelman
169113935f Fix spelling: Cannonical -> Canonical 2021-10-10 00:44:34 -04:00
Guillaume Gomez
836597a881
Rollup merge of #89649 - matthiaskrgr:clippycompl, r=jyn514
clippy::complexity fixes
2021-10-08 22:30:40 +02:00
Matthias Krüger
e6f77a1787 clippy::complexity fixes 2021-10-08 20:07:44 +02:00
bors
e0aaffd8a4 Auto merge of #89576 - tom7980:issue-89275-fix, r=estebank
Prevent error reporting from outputting a recursion error if it finds an ambiguous trait impl during suggestions

Closes #89275

This fixes the compiler reporting a recursion error during another already in progress error by trying to make a conversion method suggestion and encounters ambiguous trait implementations that can convert a the original type into a type that can then be recursively converted into itself via another method in the trait.

Updated OverflowError struct to be an enum so I could differentiate between passes - it's no longer a ZST but I don't think that should be a problem as they only generate when there's an error in compiling code anyway
2021-10-08 11:44:45 +00:00
bors
5641481ad7 Auto merge of #89629 - GuillaumeGomez:rollup-s4r8me6, r=GuillaumeGomez
Rollup of 7 pull requests

Successful merges:

 - #89298 (Issue 89193 - Fix ICE when using `usize` and `isize` with SIMD gathers )
 - #89461 (Add `deref_into_dyn_supertrait` lint.)
 - #89477 (Move items related to computing diffs to a separate file)
 - #89559 (RustWrapper: adapt for LLVM API change)
 - #89585 (Emit item no type error even if type inference fails)
 - #89596 (Make cfg imply doc(cfg))
 - #89615 (Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-10-07 17:17:25 +00:00
Guillaume Gomez
ab276b82b0
Rollup merge of #89461 - crlf0710:dyn_upcasting_lint, r=nikomatsakis
Add `deref_into_dyn_supertrait` lint.

Initial implementation of #89460. Resolves #89190.
Maybe also worth a beta backport if necessary.

r? `@nikomatsakis`
2021-10-07 16:24:49 +02:00
Cameron Steffen
33b9b95305 Introduce get_diagnostic_name 2021-10-06 08:40:28 -05:00
bors
d7539a6af0 Auto merge of #89323 - estebank:derive-binop, r=petrochenkov
Consider unfulfilled obligations in binop errors

When encountering a binop where the types would have been accepted, if
all the predicates had been fulfilled, include information about the
predicates and suggest appropriate `#[derive]`s if possible.

Fix #84515.
2021-10-06 06:20:25 +00:00
Esteban Kuber
e8fc076f23 Consider unfulfilled obligations in binop errors
When encountering a binop where the types would have been accepted, if
all the predicates had been fulfilled, include information about the
predicates and suggest appropriate `#[derive]`s if possible.

Point at trait(s) that needs to be `impl`emented.
2021-10-05 23:34:13 +00:00
Tom Farmer
0950d5afe2 Issue 89275 fix and test
Issue 89275 fix and test

Fix librustdoc OverflowError usage

rust tidy run

Issue 89275 fix and test
2021-10-05 22:43:06 +01:00
Manish Goregaokar
0352a2820d
Rollup merge of #89317 - JulianKnodt:precise_errors, r=BoxyUwU
Move generic error message to separate branches

This decomposes an error message in generic constants into more specific branches, for better
readability.

r? ``@lcnr``
2021-10-05 12:52:44 -07:00