Only prefer param-env candidates if they remain non-global after norm #140260

compiler-errors · 2025-04-24T16:11:30Z

Introduce CandidateSource::GlobalParamEnv, and dynamically compute the CandidateSource based on whether the predicate contains params post-normalization.

This code needs some cleanup and documentation. I'm just putting this up for review.

cc rust-lang/trait-system-refactor-initiative#179

r? lcnr

rustbot · 2025-04-24T16:11:36Z

HIR ty lowering was modified

cc @fmease

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs

lcnr · 2025-04-25T19:10:51Z

pls add test

trait With {
    type Assoc;
}
impl<T> With for T {
    type Assoc = T;
}

trait Incomplete<T> {}
impl<T> Incomplete<T> for () {}
fn impls_incomplete<T: Incomplete<U>, U>() {}
fn foo<T>()
where
    u32: With<Assoc = T>,
    (): Incomplete<<u32 as With>::Assoc>,
{
    impls_incomplete::<(), _>();
}

fn main() {}

edit: actually, added as part of #140313

bors · 2025-04-26T09:41:06Z

☔ The latest upstream changes (presumably #140324) made this pull request unmergeable. Please resolve the merge conflicts.

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 ~~[top 100 most downloaded crates on crates.io compile](rust-lang#133502 (comment) [top 1000 most downloaded crates on crates.io compile](rust-lang#133502 (comment)) [first perf run](rust-lang#133502 (comment)) 👻 ### in-flight changes - rust-lang#124852, unsure whether I actually want to land this PR for now - rust-lang#139587 - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140302 - rust-lang#140276 - rust-lang#140260 - rust-lang#140405 r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 ~~[top 100 most downloaded crates on crates.io compile](rust-lang#133502 (comment) [top 1000 most downloaded crates on crates.io compile](rust-lang#133502 (comment)) [first perf run](rust-lang#133502 (comment)) 👻 ### in-flight changes - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | ### in-flight changes - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | | 2025.05.03 | 624228[^1] | 1585 | [^1]: a complete crater run ### in-flight changes - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | | 2025.05.03 | 624228[^1] | 1585 | [^1]: a complete crater run ### in-flight changes - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 - double recursion limit in the new solver r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | | 2025.05.03 | 624228[^1] | 1585 | | 2025.05.05 | 8964[^2] | 931 | [^1]: a complete crater run [^2]: only testing crates which may have regressed from the above run ### in-flight changes - rust-lang#140561 - rust-lang#140672 - rust-lang#140678 - rust-lang#136997 - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 - double recursion limit in the new solver r? `@ghost`

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | | 2025.05.03 | 624228[^1] | 1585 | | 2025.05.05 | 8964[^2] | 931 | | 2025.05.06 | 4401[^2] | 726 | [^1]: a complete crater run [^2]: only testing crates which may have regressed from the above run ### in-flight changes - rust-lang#140561 - rust-lang#140672 - rust-lang#140678 - rust-lang#136997 - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - rust-lang#140496 - double recursion limit in the new solver r? `@ghost`

compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs

compiler/rustc_next_trait_solver/src/solve/effect_goals.rs

compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs

compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs

compiler/rustc_type_ir/src/solve/mod.rs

lcnr

nits, then r=me

[DO NOT MERGE] bootstrap with `-Znext-solver=globally` A revival of rust-lang#124812. Current status: ~~`./x.py b --stage 2` passes 🎉~~ `try` builds succeed 🎉 🎉 🎉 [first perf run](rust-lang#133502 (comment)) 👻 ### crater This does not detect hangs or memory issues. | date | #crates | #regressions | | ---- | ------- | ------------ | | 2025.04.11 | 100 | 2 | | 2025.04.11 | 1000 | 27 | | 2025.04.17 | 10000 | 456 | | 2025.04.18 | 10000 | 437 | | 2025.04.24 | 10000 | 164 | | 2025.04.26 | 10000 | 108 | | 2025.04.28 | 10000 | 91 | | 2025.05.01 | 10000 | 145 woops | | 2025.05.03 | 624228[^1] | 1585 | | 2025.05.05 | 8964[^2] | 931 | | 2025.05.06 | 4401[^2] | 726 | [^1]: a complete crater run [^2]: only testing crates which may have regressed from the above run ### in-flight changes - rust-lang#140711 - rust-lang#140713 - rust-lang#140712 - rust-lang#136997 - rust-lang#139587 - rust-lang#140497 - rust-lang#124852, unsure whether I actually want to land this PR for now - https://github.com/lcnr/rust/tree/opaque-type-method-call - rust-lang#140260 - rust-lang#140375 - rust-lang#140405 - look into blanket impls for opaque type infer vars as well - rust-lang#140496 - double recursion limit in the new solver r? `@ghost`

lcnr · 2025-05-07T16:50:32Z

@bors r+ rollup

bors · 2025-05-07T16:50:35Z

📌 Commit 8a21d1b has been approved by lcnr

It is now in the queue for this repository.

…orm, r=lcnr Only prefer param-env candidates if they remain non-global after norm Introduce `CandidateSource::GlobalParamEnv`, and dynamically compute the `CandidateSource` based on whether the predicate contains params *post-normalization*. This code needs some cleanup and documentation. I'm just putting this up for review. cc rust-lang/trait-system-refactor-initiative#179 r? lcnr

Rollup of 15 pull requests Successful merges: - rust-lang#138736 (Sanitizers target modificators) - rust-lang#140260 (Only prefer param-env candidates if they remain non-global after norm) - rust-lang#140523 (Better error message for late/early lifetime param mismatch) - rust-lang#140579 (Remove estebank from automated review assignment) - rust-lang#140641 (detect additional uses of opaques after writeback) - rust-lang#140711 (Do not discard constraints on overflow if there was candidate ambiguity) - rust-lang#140716 (Improve `-Zremap-path-scope` tests with dependency) - rust-lang#140755 ([win][arm64] Disable various DebugInfo tests that don't work on Arm64 Windows) - rust-lang#140756 ([arm64] Pointer auth test should link with C static library statically) - rust-lang#140758 ([win][arm64] Disable MSVC Linker 'Arm Hazard' warning) - rust-lang#140759 ([win][arm64] Disable std::fs tests that require symlinks) - rust-lang#140762 (rustdoc-json: Remove newlines from attributes) - rust-lang#140764 (style: Never break within a nullary function call `func()` or a unit literal `()`) - rust-lang#140769 (Add `DefPathData::OpaqueLifetime` to avoid conflicts for remapped opaque lifetimes) - rust-lang#140773 (triagebot: Better message for changes to `tests/rustdoc-json`) r? `@ghost` `@rustbot` modify labels: rollup

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#140260 (Only prefer param-env candidates if they remain non-global after norm) - rust-lang#140523 (Better error message for late/early lifetime param mismatch) - rust-lang#140579 (Remove estebank from automated review assignment) - rust-lang#140641 (detect additional uses of opaques after writeback) - rust-lang#140711 (Do not discard constraints on overflow if there was candidate ambiguity) - rust-lang#140762 (rustdoc-json: Remove newlines from attributes) - rust-lang#140764 (style: Never break within a nullary function call `func()` or a unit literal `()`) - rust-lang#140769 (Add `DefPathData::OpaqueLifetime` to avoid conflicts for remapped opaque lifetimes) - rust-lang#140773 (triagebot: Better message for changes to `tests/rustdoc-json`) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#140260 - compiler-errors:only-global-post-norm, r=lcnr Only prefer param-env candidates if they remain non-global after norm Introduce `CandidateSource::GlobalParamEnv`, and dynamically compute the `CandidateSource` based on whether the predicate contains params *post-normalization*. This code needs some cleanup and documentation. I'm just putting this up for review. cc rust-lang/trait-system-refactor-initiative#179 r? lcnr

rustbot assigned lcnr Apr 24, 2025

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. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver) labels Apr 24, 2025

compiler-errors force-pushed the only-global-post-norm branch from 574fcaa to a154981 Compare April 24, 2025 16:13

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lcnr reviewed Apr 25, 2025

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lcnr mentioned this pull request Apr 28, 2025

[DO NOT MERGE] bootstrap with -Znext-solver=globally #133502

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compiler-errors force-pushed the only-global-post-norm branch 2 times, most recently from c20c569 to 4750eaf Compare May 6, 2025 20:24

compiler-errors mentioned this pull request May 6, 2025

normalization: avoid incompletely constraining GAT args #140712

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