Skip to content

Fix query cycle when encounter unevaluated const #148698

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Open
wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Fix query cycle when encounter unevaluated const #148698

wants to merge 2 commits into from

Conversation

@tiif
Copy link
Member

@tiif tiif commented Nov 8, 2025

Fixes rust-lang/trait-system-refactor-initiative#249

In this PR, the environment is dropped when evaluating const that does not have any generic parameter to fix the query cycle.

@rustbot rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver) labels Nov 8, 2025
@tiif
Copy link
Member Author

tiif commented Nov 8, 2025 •
edited
Loading

I didn't do this for the GCE and RepeatExprCount path above for now because I don't think they will have the same query cycle problem? 🤔 If that should be done, feel free to let me know, and it'd be nice to have test for those paths too.

@tiif
Copy link
Member Author

tiif commented Nov 8, 2025

r? @BoxyUwU

@rustbot
Copy link
Collaborator

rustbot commented Nov 8, 2025

BoxyUwU is currently at their maximum review capacity.
They may take a while to respond.

@tiif tiif marked this pull request as ready for review November 8, 2025 16:31
@rustbot 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 Nov 8, 2025
BoxyUwU
BoxyUwU reviewed Nov 10, 2025
View reviewed changes
compiler/rustc_trait_selection/src/traits/mod.rs

// Since there is no generic parameter, we can just drop the environment
// to prevent query cycle.
if !uv.args.has_non_region_param() {
Copy link
Member

@BoxyUwU BoxyUwU Nov 10, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think you should be able to do this unconditionally because we early exit above if there are any generic parameters. can can you try always using the empty env. should also be able to get rid of the previous assignment to typing_env this way too

@BoxyUwU BoxyUwU 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 Nov 10, 2025
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@BoxyUwU BoxyUwU BoxyUwU left review comments

Assignees

@BoxyUwU BoxyUwU

Labels

S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver)

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

unevaluated consts in param_env query cycle

3 participants

@tiif @rustbot @BoxyUwU