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Don't ICE when reporting borrowck errors involving regions from anonymous_lifetime_in_impl_trait #103382

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merged 1 commit into from
Oct 25, 2022

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@compiler-errors compiler-errors commented Oct 22, 2022

The issue here is that when we have:

trait Trait<'a> { .. }

fn foo(arg: impl Trait) { .. }

The anonymous lifetime '_ that we generate for arg: impl Trait doesn't end up in the argument type (which is a param) but in a where-clause of the function, in a predicate whose self type is that param ty.

Fixes #101660

r? @cjgillot

@rustbot rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Oct 22, 2022
@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Oct 22, 2022
@compiler-errors compiler-errors changed the title Don't ICE on regions from anonymous_lifetime_in_impl_trait Don't ICE when reporting borrowck errors involving regions from anonymous_lifetime_in_impl_trait Oct 22, 2022
@compiler-errors compiler-errors force-pushed the anon-apit-lt-region-ice branch from ecbff72 to e025306 Compare October 22, 2022 03:01
error[E0521]: borrowed data escapes outside of closure
--> $DIR/anonymous-region-in-apit.rs:8:17
|
LL | fn qux(foo: impl Foo<&str>) {
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Is there any easy way to get the def_id of the lifetime itself and point to it?
r=me if not.

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No, as far as I understand it, the way that borrowck does it requires walking through HIR, and I didn't want to reinvent that for just this case.

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@bors r=cjgillot rollup

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bors commented Oct 24, 2022

📌 Commit e025306 has been approved by cjgillot

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 24, 2022
JohnTitor pushed a commit to JohnTitor/rust that referenced this pull request Oct 24, 2022
…n-ice, r=cjgillot

Don't ICE when reporting borrowck errors involving regions from `anonymous_lifetime_in_impl_trait`

The issue here is that when we have:

```
trait Trait<'a> { .. }

fn foo(arg: impl Trait) { .. }
```

The anonymous lifetime `'_` that we generate for `arg: impl Trait` doesn't end up in the argument type (which is a param) but in a where-clause of the function, in a predicate whose self type is that param ty.

Fixes rust-lang#101660

r? `@cjgillot`
bors added a commit to rust-lang-ci/rust that referenced this pull request Oct 25, 2022
Rollup of 11 pull requests

Successful merges:

 - rust-lang#103333 (Fix assertion failed for break_last_token and trailing token)
 - rust-lang#103350 (Change terminology for assoc method suggestions when they are not called)
 - rust-lang#103382 (Don't ICE when reporting borrowck errors involving regions from `anonymous_lifetime_in_impl_trait`)
 - rust-lang#103409 (Delay span bug when we can't map lifetimes back in `collect_trait_impl_trait_tys`)
 - rust-lang#103410 (-Z docs: Add link to unstable book)
 - rust-lang#103462 (rustdoc: remove no-op CSS `.source pre.rust { white-space: pre }`)
 - rust-lang#103465 (E0210 explanation: remove redundant sentence)
 - rust-lang#103486 (Use functions in highlight-colors rustdoc GUI test)
 - rust-lang#103493 (rustdoc: remove unused `.sidebar-logo` DOM on source pages)
 - rust-lang#103494 (rustdoc: remove redundant CSS `a.test-arrow:hover`)
 - rust-lang#103495 (rustdoc: Use `unix_sigpipe` instead of `rustc_driver::set_sigpipe_handler`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 6383540 into rust-lang:master Oct 25, 2022
@rustbot rustbot added this to the 1.66.0 milestone Oct 25, 2022
@compiler-errors compiler-errors deleted the anon-apit-lt-region-ice branch November 2, 2022 02:53
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[ICE] [Nightly] Compiler panicks on anonymous lifetime in impl Trait
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