`impl` restriction lowering#153556

CoCo-Japan-pan · 2026-03-08T07:38:09Z

This PR is linked to a GSoC proposal and is part of the progress toward implementing impl restrictions proposed in RFC 3323.
This PR implements path resolution for impl restrictions. The resolution is performed in rustc_resolve/src/late.rs using smart_resolve_path.
This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s AncestorOnly error.

r? @Urgau
cc @jhpratt

Urgau

Looks pretty good. Only some nits.

View changes since this review

compiler/rustc_resolve/src/build_reduced_graph.rs

tests/ui/impl-restriction/restriction_resolution_errors.rs

tests/ui/impl-restriction/restriction_resolution_2018.rs

compiler/rustc_resolve/src/lib.rs

CoCo-Japan-pan · 2026-03-08T13:44:15Z

Thanks for the review!
@rustbot ready

Urgau

Looks mostly good, just need some positive tests now.

View changes since this review

tests/ui/impl-restriction/restriction_resolution_2018.rs

Urgau

Looks good to me. I will let @jhpratt do the final review.

View changes since this review

compiler/rustc_resolve/src/build_reduced_graph.rs

compiler/rustc_resolve/src/late.rs

compiler/rustc_middle/src/hir/map.rs

CoCo-Japan-pan · 2026-03-16T17:16:01Z

The current implementation uses smart_resolve_path.
I added a new variant, PathSource::Module.

I kept the ancestor check and pushed it into use_injections to keep the error emission order consistent with its occurrence.
Currently, the "too many leading super keywords" error is emitted first regardless of the occurrence order, but this seems to be a separate issue.
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2024&gist=05164a046abf4e1c123793c0037c06a7

@rustbot ready

tests/ui/impl-restriction/restriction_resolution_use.rs

tests/ui/impl-restriction/restriction_resolution_errors.rs

compiler/rustc_resolve/src/lib.rs

compiler/rustc_middle/src/ty/mod.rs

compiler/rustc_resolve/src/late.rs

CoCo-Japan-pan · 2026-03-19T10:15:30Z

@rustbot ready

petrochenkov · 2026-03-19T10:18:27Z

@bors r+

rust-bors · 2026-03-19T10:18:31Z

📌 Commit 4a60dae has been approved by petrochenkov

It is now in the queue for this repository.

@Urgau

…wering, r=petrochenkov `impl` restriction lowering This PR is linked to a [GSoC proposal](https://github.com/rust-lang/google-summer-of-code?tab=readme-ov-file#implementing-impl-and-mut-restrictions) and is part of the progress toward implementing `impl` restrictions proposed in [RFC 3323](https://rust-lang.github.io/rfcs/3323-restrictions.html). This PR implements path resolution for `impl` restrictions. The resolution is performed in `rustc_resolve/src/late.rs` using `smart_resolve_path`. This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s `AncestorOnly` error. r? @Urgau cc @jhpratt

…uwer Rollup of 9 pull requests Successful merges: - #153556 (`impl` restriction lowering) - #153992 (bootstrap: Optionally print a backtrace if a command fails) - #154019 (two smaller feature cleanups) - #154059 (tests: Activate `must_not_suspend` test for `MutexGuard` dropped before `await`) - #154075 (Rewrite `query_ensure_result`.) - #154082 (Updates derive_where and removes workaround) - #154084 (Preserve braces around `self` in use tree pretty printing) - #154086 (Insert space after float literal ending with `.` in pretty printer) - #154087 (Fix whitespace after fragment specifiers in macro pretty printing)

@Urgau

…wering, r=petrochenkov `impl` restriction lowering This PR is linked to a [GSoC proposal](https://github.com/rust-lang/google-summer-of-code?tab=readme-ov-file#implementing-impl-and-mut-restrictions) and is part of the progress toward implementing `impl` restrictions proposed in [RFC 3323](https://rust-lang.github.io/rfcs/3323-restrictions.html). This PR implements path resolution for `impl` restrictions. The resolution is performed in `rustc_resolve/src/late.rs` using `smart_resolve_path`. This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s `AncestorOnly` error. r? @Urgau cc @jhpratt

@Urgau

…wering, r=petrochenkov `impl` restriction lowering This PR is linked to a [GSoC proposal](https://github.com/rust-lang/google-summer-of-code?tab=readme-ov-file#implementing-impl-and-mut-restrictions) and is part of the progress toward implementing `impl` restrictions proposed in [RFC 3323](https://rust-lang.github.io/rfcs/3323-restrictions.html). This PR implements path resolution for `impl` restrictions. The resolution is performed in `rustc_resolve/src/late.rs` using `smart_resolve_path`. This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s `AncestorOnly` error. r? @Urgau cc @jhpratt

@Urgau

…wering, r=petrochenkov `impl` restriction lowering This PR is linked to a [GSoC proposal](https://github.com/rust-lang/google-summer-of-code?tab=readme-ov-file#implementing-impl-and-mut-restrictions) and is part of the progress toward implementing `impl` restrictions proposed in [RFC 3323](https://rust-lang.github.io/rfcs/3323-restrictions.html). This PR implements path resolution for `impl` restrictions. The resolution is performed in `rustc_resolve/src/late.rs` using `smart_resolve_path`. This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s `AncestorOnly` error. r? @Urgau cc @jhpratt

@Urgau

…wering, r=petrochenkov `impl` restriction lowering This PR is linked to a [GSoC proposal](https://github.com/rust-lang/google-summer-of-code?tab=readme-ov-file#implementing-impl-and-mut-restrictions) and is part of the progress toward implementing `impl` restrictions proposed in [RFC 3323](https://rust-lang.github.io/rfcs/3323-restrictions.html). This PR implements path resolution for `impl` restrictions. The resolution is performed in `rustc_resolve/src/late.rs` using `smart_resolve_path`. This PR also checks whether the restricted module or crate is an ancestor. If it is not, it emits a restriction-specific counterpart to visibility’s `AncestorOnly` error. r? @Urgau cc @jhpratt

…uwer Rollup of 12 pull requests Successful merges: - #152909 (sess: `-Zbranch-protection` is a target modifier) - #153556 (`impl` restriction lowering) - #154048 (Don't emit rustdoc `missing_doc_code_examples` lint on impl items) - #153992 (bootstrap: Optionally print a backtrace if a command fails) - #154019 (two smaller feature cleanups) - #154059 (tests: Activate `must_not_suspend` test for `MutexGuard` dropped before `await`) - #154075 (Rewrite `query_ensure_result`.) - #154082 (Updates derive_where and removes workaround) - #154084 (Preserve braces around `self` in use tree pretty printing) - #154086 (Insert space after float literal ending with `.` in pretty printer) - #154087 (Fix whitespace after fragment specifiers in macro pretty printing) - #154109 (tests: Add regression test for async closures involving HRTBs)

Rollup of 15 pull requests Successful merges: - #152909 (sess: `-Zbranch-protection` is a target modifier) - #153556 (`impl` restriction lowering) - #154048 (Don't emit rustdoc `missing_doc_code_examples` lint on impl items) - #150935 (Introduce #[diagnostic::on_move(message)]) - #152973 (remove -Csoft-float) - #153862 (Rename `cycle_check` to `find_cycle`) - #153992 (bootstrap: Optionally print a backtrace if a command fails) - #154019 (two smaller feature cleanups) - #154059 (tests: Activate `must_not_suspend` test for `MutexGuard` dropped before `await`) - #154075 (Rewrite `query_ensure_result`.) - #154082 (Updates derive_where and removes workaround) - #154084 (Preserve braces around `self` in use tree pretty printing) - #154086 (Insert space after float literal ending with `.` in pretty printer) - #154087 (Fix whitespace after fragment specifiers in macro pretty printing) - #154109 (tests: Add regression test for async closures involving HRTBs)

@Urgau

…eck, r=jhpratt,Urgau Semantic checks of `impl` restrictions This PR implements semantic checks for `impl` restrictions proposed in the [Restrictions RFC](https://rust-lang.github.io/rfcs/3323-restrictions.html) (Tracking Issue rust-lang#105077), and linked to a [GSOC idea/proposal](https://github.com/rust-lang/google-summer-of-code/tree/142433eb3b104b2f32bae0b9dfafb78a0a2ac579?tab=readme-ov-file#implementing-impl-and-mut-restrictions). It lowers the resolved paths of `impl` restrictions from the AST to HIR and into `TraitDef`, and integrates the checks into the coherence phase by extending `check_impl`. As parsing (rust-lang#152943) and path resolution (rust-lang#153556) have already been implemented, this PR provides a working implementation of `impl` restrictions. r? @Urgau cc @jhpratt

@Urgau

…eck, r=jhpratt,Urgau Semantic checks of `impl` restrictions This PR implements semantic checks for `impl` restrictions proposed in the [Restrictions RFC](https://rust-lang.github.io/rfcs/3323-restrictions.html) (Tracking Issue rust-lang#105077), and linked to a [GSOC idea/proposal](https://github.com/rust-lang/google-summer-of-code/tree/142433eb3b104b2f32bae0b9dfafb78a0a2ac579?tab=readme-ov-file#implementing-impl-and-mut-restrictions). It lowers the resolved paths of `impl` restrictions from the AST to HIR and into `TraitDef`, and integrates the checks into the coherence phase by extending `check_impl`. As parsing (rust-lang#152943) and path resolution (rust-lang#153556) have already been implemented, this PR provides a working implementation of `impl` restrictions. r? @Urgau cc @jhpratt

@Urgau

Rollup merge of #154661 - CoCo-Japan-pan:impl-restriction-check, r=jhpratt,Urgau Semantic checks of `impl` restrictions This PR implements semantic checks for `impl` restrictions proposed in the [Restrictions RFC](https://rust-lang.github.io/rfcs/3323-restrictions.html) (Tracking Issue #105077), and linked to a [GSOC idea/proposal](https://github.com/rust-lang/google-summer-of-code/tree/142433eb3b104b2f32bae0b9dfafb78a0a2ac579?tab=readme-ov-file#implementing-impl-and-mut-restrictions). It lowers the resolved paths of `impl` restrictions from the AST to HIR and into `TraitDef`, and integrates the checks into the coherence phase by extending `check_impl`. As parsing (#152943) and path resolution (#153556) have already been implemented, this PR provides a working implementation of `impl` restrictions. r? @Urgau cc @jhpratt

rustbot assigned Urgau Mar 8, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Mar 8, 2026

CoCo-Japan-pan changed the title ~~Impl restriction lowering~~ impl restriction lowering Mar 8, 2026

Urgau reviewed Mar 8, 2026

View reviewed changes

Urgau added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 8, 2026

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch 2 times, most recently from deed8e1 to 596133b Compare March 8, 2026 13:38

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Mar 8, 2026

Urgau reviewed Mar 8, 2026

View reviewed changes

tests/ui/impl-restriction/restriction_resolution_2018.rs Outdated Show resolved Hide resolved

tests/ui/impl-restriction/restriction_resolution_2018.rs Outdated Show resolved Hide resolved

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch from 596133b to 40df631 Compare March 9, 2026 06:47

Urgau approved these changes Mar 9, 2026

View reviewed changes

petrochenkov reviewed Mar 10, 2026

View reviewed changes

compiler/rustc_resolve/src/build_reduced_graph.rs Outdated Show resolved Hide resolved

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch from 40df631 to dcc1cf5 Compare March 10, 2026 16:52

CoCo-Japan-pan requested a review from Urgau March 10, 2026 17:51

Urgau assigned petrochenkov Mar 15, 2026

petrochenkov reviewed Mar 16, 2026

View reviewed changes

compiler/rustc_resolve/src/late.rs Show resolved Hide resolved

compiler/rustc_middle/src/hir/map.rs Outdated Show resolved Hide resolved

petrochenkov added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 16, 2026

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch 2 times, most recently from f1ef729 to 020ae2b Compare March 16, 2026 17:01

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Mar 16, 2026

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch 2 times, most recently from 482cd56 to 54e564c Compare March 17, 2026 13:57

petrochenkov reviewed Mar 18, 2026

View reviewed changes

CoCo-Japan-pan added 2 commits March 19, 2026 19:05

Resolve paths for impl restrictions using smart_resolve_path

cec0a68

Add UI tests for path resolution errors of impl restrictions

4a60dae

CoCo-Japan-pan force-pushed the impl-restriction-lowering branch from 8cfbc47 to 4a60dae Compare March 19, 2026 10:11

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Mar 19, 2026

rust-bors bot 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 Mar 19, 2026

JonathanBrouwer mentioned this pull request Mar 19, 2026

Rollup of 9 pull requests #154102

Closed

JonathanBrouwer mentioned this pull request Mar 19, 2026

Rollup of 12 pull requests #154116

Closed

JonathanBrouwer mentioned this pull request Mar 19, 2026

Rollup of 12 pull requests #154117

Closed

Zalathar mentioned this pull request Mar 20, 2026

Rollup of 15 pull requests #154123

Merged

rust-bors bot merged commit 85b8c32 into rust-lang:main Mar 20, 2026
11 checks passed

rustbot added this to the 1.96.0 milestone Mar 20, 2026

CoCo-Japan-pan mentioned this pull request Apr 1, 2026

Semantic checks of impl restrictions #154661

Merged

Urgau mentioned this pull request Apr 5, 2026

Tracking Issue for Restrictions #105077

Open

9 tasks

Uh oh!

Conversation

CoCo-Japan-pan commented Mar 8, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Urgau left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

CoCo-Japan-pan commented Mar 8, 2026

Uh oh!

Urgau left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Urgau left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

CoCo-Japan-pan commented Mar 16, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

CoCo-Japan-pan commented Mar 19, 2026

Uh oh!

petrochenkov commented Mar 19, 2026

Uh oh!

rust-bors bot commented Mar 19, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

CoCo-Japan-pan commented Mar 8, 2026 •

edited

Loading

Urgau left a comment •

edited by rustbot

Loading

Urgau left a comment •

edited by rustbot

Loading

Urgau left a comment •

edited by rustbot

Loading