Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` #136971

LFS6502 · 2025-02-13T11:41:52Z

This PR closes #107883 by adding a ui test.

rustbot · 2025-02-13T11:42:03Z

rustbot has assigned @fmease.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

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LFS6502 · 2025-02-13T11:42:15Z

r? WaffleLapkin

LFS6502 · 2025-02-13T11:44:27Z

I need some ideas for what to call this test. I thought rpit-fn-trait-rpit but I'm not convinced.

tests/ui/idk-what-to-call-this.rs

fmease

The test should be placed under tests/ui/impl-trait/.

Regarding naming, it would help to bisect the reprogression (e.g., with cargo-bisect-rustc) and see what PR made it compile and more importantly why (it didn't compile and now does). Moreover, looking at that PR could help us determine if we need extra regression tests at all or if it's sufficiently covered already.

LFS6502 · 2025-02-13T12:23:11Z

I ran the bisection

bisect-rustc results

cargo bisect-rustc --start=2023-02-10 --end=2024-07-20 --regress success

RESULT: nightly-2024-04-10, ===> Successfully compiled
uninstalling nightly-2024-04-10

searched toolchains nightly-2023-02-10 through nightly-2024-07-20

Regression in nightly-2024-04-10

fetching https://static.rust-lang.org/dist/2024-04-09/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2024-04-09: 40 B / 40 B [================================================================================================] 100.00 % 1.48 MB/s converted 2024-04-09 to ab5bda1
fetching https://static.rust-lang.org/dist/2024-04-10/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2024-04-10: 40 B / 40 B [================================================================================================] 100.00 % 1.65 MB/s converted 2024-04-10 to 8b2459c
looking for regression commit between 2024-04-09 and 2024-04-10
fetching (via remote github) commits from max(ab5bda1, 2024-04-07) to 8b2459c
ending github query because we found starting sha: ab5bda1
get_commits_between returning commits, len: 10
commit[0] 2024-04-08: Auto merge of #123645 - matthiaskrgr:rollup-yd8d7f1, r=matthiaskrgr
commit[1] 2024-04-08: Auto merge of #122077 - oli-obk:eager_opaque_checks4, r=lcnr
commit[2] 2024-04-09: Auto merge of #122387 - DianQK:re-enable-early-otherwise-branch, r=cjgillot
commit[3] 2024-04-09: Auto merge of #123099 - oli-obk:span_tcx, r=petrochenkov
commit[4] 2024-04-09: Auto merge of #123663 - matthiaskrgr:rollup-1qnj9j3, r=matthiaskrgr
commit[5] 2024-04-09: Auto merge of #123272 - saethlin:reachable-mono-cleanup, r=cjgillot
commit[6] 2024-04-09: Auto merge of #123631 - oli-obk:fail_slow, r=jieyouxu
commit[7] 2024-04-09: Auto merge of #123676 - GuillaumeGomez:rollup-1hurixy, r=GuillaumeGomez
commit[8] 2024-04-09: Auto merge of #123485 - madsmtm:use-libc-copyfile, r=joboet
commit[9] 2024-04-09: Auto merge of #123683 - pietroalbini:pa-cve-2024-24576-nightly, r=pietroalbini
ERROR: no CI builds available between ab5bda1 and 8b2459c within last 167 days

fmease · 2025-02-13T13:25:46Z

Likely #122077

LFS6502 · 2025-02-13T14:02:39Z

I've begun doing a manual bisect to be sure.

LFS6502 · 2025-02-13T14:42:55Z

Likely #122077

This is correct.

ab5bda1 fails the test
b234e44 passes the test

#122077

LFS6502 · 2025-02-13T15:05:05Z

Output when compiling the test with b234e44

Errors

rustc +stage1 ../bisect-test
error: concrete type differs from previous defining opaque type use
 --> ../bisect-test:9:10
  |
9 |     |_x| 15
  |          ^^ expected `impl Debug`, got `i32`
  |
note: previous use here
 --> ../bisect-test:9:5
  |
9 |     |_x| 15
  |     ^^^^^^^

error[E0720]: cannot resolve opaque type
 --> ../bisect-test:8:28
  |
8 | fn f<T>() -> impl Fn(T) -> impl Debug {
  |                            ^^^^^^^^^^ cannot resolve opaque type

error: concrete type differs from previous defining opaque type use
  --> ../bisect-test:25:10
   |
25 |     |_x| 15
   |          ^^ expected `impl Debug`, got `i32`
   |
note: previous use here
  --> ../bisect-test:25:5
   |
25 |     |_x| 15
   |     ^^^^^^^

error[E0720]: cannot resolve opaque type
  --> ../bisect-test:24:37
   |
24 | fn h<T>() -> impl Fn<(T,), Output = impl Debug> {
   |                                     ^^^^^^^^^^ cannot resolve opaque type

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0720`.`

Now it's a matter of deciding what the test name should be.

LFS6502 · 2025-02-13T22:53:15Z

@WaffleLapkin It's ready

@fmease I implemented your feedback, thanks!

WaffleLapkin

just a single nitpick and this can be merged :)

tests/ui/impl-trait/impl-fn-rpit-opaque-107883.rs

Change description from compiletest to regression test Co-authored-by: 许杰友 Jieyou Xu (Joe) <39484203+jieyouxu@users.noreply.github.com> Improve test name, location, and description Update tests/ui/impl-trait/impl-fn-rpit-opaque-107883.rs Co-authored-by: waffle <waffle.lapkin@gmail.com>

LFS6502 · 2025-02-14T12:57:03Z

Thanks!

WaffleLapkin · 2025-02-14T14:33:11Z

@bors r+ rollup

bors · 2025-02-14T14:33:14Z

📌 Commit 7d1262a has been approved by WaffleLapkin

It is now in the queue for this repository.

Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` This PR closes rust-lang#107883 by adding a ui test.

Rollup of 11 pull requests Successful merges: - rust-lang#133312 (triagebot: automatically add more rustdoc related labels) - rust-lang#134016 (Stabilize `const_is_char_boundary` and `const_str_split_at`.) - rust-lang#135813 (CI: split i686-mingw job to three free runners) - rust-lang#136879 (Add safe new() to NotAllOnes) - rust-lang#136971 (Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait`) - rust-lang#136983 (Prepare standard library for Rust 2024 migration) - rust-lang#137002 (Fix early lint check desc in query) - rust-lang#137006 (borrowck diagnostics cleanup: remove an unused and a barely-used field) - rust-lang#137026 (Stabilize (and const-stabilize) `integer_sign_cast`) - rust-lang#137028 (mir_build: Clarify some code for lowering `hir::PatExpr` to THIR) - rust-lang#137032 (Decode metadata buffer in one go) r? `@ghost` `@rustbot` modify labels: rollup

…kingjubilee Rollup of 10 pull requests Successful merges: - rust-lang#133312 (triagebot: automatically add more rustdoc related labels) - rust-lang#134016 (Stabilize `const_is_char_boundary` and `const_str_split_at`.) - rust-lang#136971 (Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait`) - rust-lang#136983 (Prepare standard library for Rust 2024 migration) - rust-lang#137002 (Fix early lint check desc in query) - rust-lang#137006 (borrowck diagnostics cleanup: remove an unused and a barely-used field) - rust-lang#137032 (Decode metadata buffer in one go) - rust-lang#137035 (Normalize closure instance before eagerly monomorphizing it) - rust-lang#137037 (add x86-sse2 (32bit) ABI that requires SSE2 target feature) - rust-lang#137038 (llvm: Tolerate captures in tests) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#136971 - HypheX:patch1, r=WaffleLapkin Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` This PR closes rust-lang#107883 by adding a ui test.

rustbot assigned fmease Feb 13, 2025

rustbot added S-waiting-on-review T-compiler labels Feb 13, 2025

rustbot assigned WaffleLapkin and unassigned fmease Feb 13, 2025

LFS6502 marked this pull request as ready for review February 13, 2025 11:45

LFS6502 changed the title ~~Add a new check-pass UI test for Returning impl Fn(T) -> impl Trait~~ Add a new check-pass UI test for returning impl Fn(T) -> impl Trait Feb 13, 2025

jieyouxu reviewed Feb 13, 2025

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tests/ui/idk-what-to-call-this.rs Outdated Show resolved Hide resolved

fmease reviewed Feb 13, 2025

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LFS6502 marked this pull request as draft February 13, 2025 11:56

LFS6502 force-pushed the patch1 branch from af2761c to 6cfa6e2 Compare February 13, 2025 22:51

LFS6502 marked this pull request as ready for review February 13, 2025 22:51

WaffleLapkin requested changes Feb 14, 2025

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tests/ui/impl-trait/impl-fn-rpit-opaque-107883.rs Outdated Show resolved Hide resolved

rustbot added S-waiting-on-author and removed S-waiting-on-review labels Feb 14, 2025

LFS6502 force-pushed the patch1 branch from 3784644 to 7d1262a Compare February 14, 2025 12:56

bors removed the S-waiting-on-author label Feb 14, 2025

bors added the S-waiting-on-bors label Feb 14, 2025

jhpratt added a commit to jhpratt/rust that referenced this pull request Feb 14, 2025

Rollup merge of rust-lang#136971 - HypheX:patch1, r=WaffleLapkin

8356c09

Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` This PR closes rust-lang#107883 by adding a ui test.

jhpratt mentioned this pull request Feb 14, 2025

Rollup of 11 pull requests #137040

Closed

workingjubilee mentioned this pull request Feb 14, 2025

Rollup of 10 pull requests #137046

Merged

bors merged commit 2ec48fb into rust-lang:master Feb 15, 2025
6 checks passed

rustbot added this to the 1.86.0 milestone Feb 15, 2025

LFS6502 deleted the patch1 branch February 15, 2025 05:04

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Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` #136971

Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` #136971

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Add a new check-pass UI test for returning impl Fn(T) -> impl Trait #136971

Add a new check-pass UI test for returning impl Fn(T) -> impl Trait #136971

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Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` #136971

Add a new check-pass UI test for returning `impl Fn(T) -> impl Trait` #136971

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