rework min_choice algorithm of member constraints #105300

aliemjay · 2022-12-05T13:14:38Z

See this comment for the description of the new algorithm.

This uses a more general algorithm than #89056 that doesn't treat 'static as a special case. It thus accepts more code. For example:

async fn test2<'s>(_: &'s u8, _: &'_ &'s u8, _: &'_ &'s u8) {}

I claim it's more correct as well because it fixes #104639.

cc @nikomatsakis @lqd @tmandry @eholk @chenyukang @oli-obk

r? types

compiler-errors · 2022-12-07T16:56:20Z

r? types

bors · 2022-12-15T05:02:32Z

☔ The latest upstream changes (presumably #104765) made this pull request unmergeable. Please resolve the merge conflicts.

c410-f3r · 2022-12-15T16:24:05Z

Nice! Looking forward to see #63033 fixed.

oli-obk · 2023-01-10T08:25:57Z

could you rebase and bless? I'll start a T-types FCP then

oli-obk · 2023-01-16T11:42:55Z

@rfcbot fcp merge. This PR (similarly, and building on top of #104765) allows RPITs and async fns to untangle their lifetime bounds to figure out the set of lifetimes that actually get caputed instead of falling back to a larger one or even 'static. For most cases it was was already possible for users to manually reorder their lifetimes to make their code compile, this PR just makes that automatic, as the order of generic params and bounds should not matter.

aliemjay · 2023-01-16T16:46:38Z

This PR modifies the minimal choice algorithm described here. The goal of this algorithm is to pick up the minimum of a set of universal regions related by universal_region_relations. Because universal_region_relations is not a total order relation, a unique minimum choice may not always exist. An example of this is shown in the inline comment where ['static, 'a, 'b, 'c, 'd, 'e] are related by this graph (transitive edges were removed for simplicity):

In this example, the minimal choice is ambiguous with two candidates ['d, 'e]. We used to bail out in this case (#63033). This PR however picks up the least upper bound of the two candidates LUB(['d, 'e]), which happens to be 'c.

Forward compatibility

In the future we may want to use instead a new region that represents the greatest lower bound of the candidates ReGLB(['d, 'e]) (the intersection regions proposal, if I understand it correctly), but this would still be backwards compatible with this PR because we would infer a lower region value GLB(['d, 'e]) <= LUB(['d, 'e]) (at least this is my understanding of region inference).

See test/ui/nll/member-constraints/min-choice-reject-ambiguous.rs for a test that should pass with intersection regions proposal.

Implementation

TODO: explain the implementation

See the inline comments for the description of the new algorithm.

compiler-errors · 2023-01-18T15:15:15Z

@rfcbot fcp merge

oli's FCP didn't start -- copied from that:

This PR (similarly, and building on top of #104765) allows RPITs and async fns to untangle their lifetime bounds to figure out the set of lifetimes that actually get caputed instead of falling back to a larger one or even 'static. For most cases it was was already possible for users to manually reorder their lifetimes to make their code compile, this PR just makes that automatic, as the order of generic params and bounds should not matter.

rfcbot · 2023-01-18T15:15:17Z

Team member @compiler-errors has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

Swatinem · 2023-01-30T11:57:49Z

Out of curiosity, I tried this PR on top of #104833 and it solves the bogus lifetime errors I see:

hidden type for impl Future<Output = ...> captures lifetime that does not appear in bounds

Looks like identity_future is an example of point 2 in #63033:

Seemingly insignificant tweaks, like adding a wrapper struct, make it compile.

oli-obk · 2023-02-04T12:20:08Z

@bors delegate+

r=me once the FCP finishes (@bors r=oli-obk is the invocation needed to approve in my name). Here's me 🤞-ing that bors doesn't pick up the command in backticks

bors · 2023-02-04T12:20:11Z

✌️ @aliemjay can now approve this pull request

rfcbot · 2023-02-12T14:09:08Z

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

aliemjay · 2023-02-13T06:45:06Z

@bors r=oli-obk

bors · 2023-02-13T06:45:07Z

📌 Commit 837c1af has been approved by oli-obk

It is now in the queue for this repository.

rework min_choice algorithm of member constraints See [this comment](rust-lang#105300 (comment)) for the description of the new algorithm. Fixes rust-lang#63033 Fixes rust-lang#104639 This uses a more general algorithm than rust-lang#89056 that doesn't treat `'static` as a special case. It thus accepts more code. For example: ```rust async fn test2<'s>(_: &'s u8, _: &'_ &'s u8, _: &'_ &'s u8) {} ``` I claim it's more correct as well because it fixes rust-lang#104639. cc `@nikomatsakis` `@lqd` `@tmandry` `@eholk` `@chenyukang` `@oli-obk` r? types

Rollup of 7 pull requests Successful merges: - rust-lang#105300 (rework min_choice algorithm of member constraints) - rust-lang#107163 (Remove some superfluous type parameters from layout.rs.) - rust-lang#107173 (Suggest the correct array length on mismatch) - rust-lang#107411 (Handle discriminant in DataflowConstProp) - rust-lang#107968 (Enable `#[thread_local]` on armv6k-nintendo-3ds) - rust-lang#108032 (Un📦ing the Resolver) - rust-lang#108060 (Revert to using `RtlGenRandom` as a fallback) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup

Pkgsrc changes: * Adjust patches and cargo checksums to new versions. * Sadly, the patch to reduce the cargo verbosity no longer applies, so I've asked upstream about the proper way to get the old result. (so the build log becomes Quite Bloated for now). Upstream changes: Version 1.69.0 (2023-04-20) ========================== Language -------- - [Deriving built-in traits on packed structs works with `Copy` fields.] (rust-lang/rust#104429) - [Stabilize the `cmpxchg16b` target feature on x86 and x86_64.] (rust-lang/rust#106774) - [Improve analysis of trait bounds for associated types.] (rust-lang/rust#103695) - [Allow associated types to be used as union fields.] (rust-lang/rust#106938) - [Allow `Self: Autotrait` bounds on dyn-safe trait methods.] (rust-lang/rust#107082) - [Treat `str` as containing `[u8]` for auto trait purposes.] (rust-lang/rust#107941) Compiler -------- - [Upgrade `*-pc-windows-gnu` on CI to mingw-w64 v10 and GCC 12.2.] (rust-lang/rust#100178) - [Rework min_choice algorithm of member constraints.] (rust-lang/rust#105300) - [Support `true` and `false` as boolean flags in compiler arguments.] (rust-lang/rust#107043) - [Default `repr(C)` enums to `c_int` size.] (rust-lang/rust#107592) Libraries --------- - [Implement the unstable `DispatchFromDyn` for cell types, allowing downstream experimentation with custom method receivers.] (rust-lang/rust#97373) - [Document that `fmt::Arguments::as_str()` may return `Some(_)` in more cases after optimization, subject to change.] (rust-lang/rust#106823) - [Implement `AsFd` and `AsRawFd` for `Rc`.] (rust-lang/rust#107317) Stabilized APIs --------------- - [`CStr::from_bytes_until_nul`] (https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html#method.from_bytes_until_nul) - [`core::ffi::FromBytesUntilNulError`] (https://doc.rust-lang.org/stable/core/ffi/struct.FromBytesUntilNulError.html) These APIs are now stable in const contexts: - [`SocketAddr::new`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.new) - [`SocketAddr::ip`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.ip) - [`SocketAddr::port`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.port) - [`SocketAddr::is_ipv4`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.is_ipv4) - [`SocketAddr::is_ipv6`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.is_ipv6) - [`SocketAddrV4::new`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.new) - [`SocketAddrV4::ip`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.ip) - [`SocketAddrV4::port`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.port) - [`SocketAddrV6::new`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.new) - [`SocketAddrV6::ip`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.ip) - [`SocketAddrV6::port`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.port) - [`SocketAddrV6::flowinfo`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.flowinfo) - [`SocketAddrV6::scope_id`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.scope_id) Cargo ----- - [Cargo now suggests `cargo fix` or `cargo clippy --fix` when compilation warnings are auto-fixable.] (rust-lang/cargo#11558) - [Cargo now suggests `cargo add` if you try to install a library crate.] (rust-lang/cargo#11410) - [Cargo now sets the `CARGO_BIN_NAME` environment variable also for binary examples.] (rust-lang/cargo#11705) Rustdoc ----- - [Vertically compact trait bound formatting.] (rust-lang/rust#102842) - [Only include stable lints in `rustdoc::all` group.] (rust-lang/rust#106316) - [Compute maximum Levenshtein distance based on the query.] (rust-lang/rust#107141) - [Remove inconsistently-present sidebar tooltips.] (rust-lang/rust#107490) - [Search by macro when query ends with `!`.] (rust-lang/rust#108143) Compatibility Notes ------------------- - [The `rust-analysis` component from `rustup` now only contains a warning placeholder.] (rust-lang/rust#101841) This was primarily intended for RLS, and the corresponding `-Zsave-analysis` flag has been removed from the compiler as well. - [Unaligned references to packed fields are now a hard error.] (rust-lang/rust#102513) This has been a warning since 1.53, and denied by default with a future-compatibility warning since 1.62. - [Update the minimum external LLVM to 14.] (rust-lang/rust#107573) - [Cargo now emits errors on invalid characters in a registry token.] (rust-lang/cargo#11600) - [When `default-features` is set to false of a workspace dependency, and an inherited dependency of a member has `default-features = true`, Cargo will enable default features of that dependency.] (rust-lang/cargo#11409) - [Cargo denies `CARGO_HOME` in the `[env]` configuration table. Cargo itself doesn't pick up this value, but recursive calls to cargo would, which was not intended.] (rust-lang/cargo#11644) - [Debuginfo for build dependencies is now off if not explicitly set. This is expected to improve the overall build time.] (rust-lang/cargo#11252) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Move `format_args!()` into AST (and expand it during AST lowering)] (rust-lang/rust#106745)

Pkgsrc changes: * Adjust patches and cargo checksums to new versions. Upstream changes: Version 1.69.0 (2023-04-20) ========================== Language -------- - [Deriving built-in traits on packed structs works with `Copy` fields.] (rust-lang/rust#104429) - [Stabilize the `cmpxchg16b` target feature on x86 and x86_64.] (rust-lang/rust#106774) - [Improve analysis of trait bounds for associated types.] (rust-lang/rust#103695) - [Allow associated types to be used as union fields.] (rust-lang/rust#106938) - [Allow `Self: Autotrait` bounds on dyn-safe trait methods.] (rust-lang/rust#107082) - [Treat `str` as containing `[u8]` for auto trait purposes.] (rust-lang/rust#107941) Compiler -------- - [Upgrade `*-pc-windows-gnu` on CI to mingw-w64 v10 and GCC 12.2.] (rust-lang/rust#100178) - [Rework min_choice algorithm of member constraints.] (rust-lang/rust#105300) - [Support `true` and `false` as boolean flags in compiler arguments.] (rust-lang/rust#107043) - [Default `repr(C)` enums to `c_int` size.] (rust-lang/rust#107592) Libraries --------- - [Implement the unstable `DispatchFromDyn` for cell types, allowing downstream experimentation with custom method receivers.] (rust-lang/rust#97373) - [Document that `fmt::Arguments::as_str()` may return `Some(_)` in more cases after optimization, subject to change.] (rust-lang/rust#106823) - [Implement `AsFd` and `AsRawFd` for `Rc`.] (rust-lang/rust#107317) Stabilized APIs --------------- - [`CStr::from_bytes_until_nul`] (https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html#method.from_bytes_until_nul) - [`core::ffi::FromBytesUntilNulError`] (https://doc.rust-lang.org/stable/core/ffi/struct.FromBytesUntilNulError.html) These APIs are now stable in const contexts: - [`SocketAddr::new`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.new) - [`SocketAddr::ip`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.ip) - [`SocketAddr::port`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.port) - [`SocketAddr::is_ipv4`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.is_ipv4) - [`SocketAddr::is_ipv6`] (https://doc.rust-lang.org/stable/std/net/enum.SocketAddr.html#method.is_ipv6) - [`SocketAddrV4::new`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.new) - [`SocketAddrV4::ip`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.ip) - [`SocketAddrV4::port`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV4.html#method.port) - [`SocketAddrV6::new`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.new) - [`SocketAddrV6::ip`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.ip) - [`SocketAddrV6::port`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.port) - [`SocketAddrV6::flowinfo`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.flowinfo) - [`SocketAddrV6::scope_id`] (https://doc.rust-lang.org/stable/std/net/struct.SocketAddrV6.html#method.scope_id) Cargo ----- - [Cargo now suggests `cargo fix` or `cargo clippy --fix` when compilation warnings are auto-fixable.] (rust-lang/cargo#11558) - [Cargo now suggests `cargo add` if you try to install a library crate.] (rust-lang/cargo#11410) - [Cargo now sets the `CARGO_BIN_NAME` environment variable also for binary examples.] (rust-lang/cargo#11705) Rustdoc ----- - [Vertically compact trait bound formatting.] (rust-lang/rust#102842) - [Only include stable lints in `rustdoc::all` group.] (rust-lang/rust#106316) - [Compute maximum Levenshtein distance based on the query.] (rust-lang/rust#107141) - [Remove inconsistently-present sidebar tooltips.] (rust-lang/rust#107490) - [Search by macro when query ends with `!`.] (rust-lang/rust#108143) Compatibility Notes ------------------- - [The `rust-analysis` component from `rustup` now only contains a warning placeholder.] (rust-lang/rust#101841) This was primarily intended for RLS, and the corresponding `-Zsave-analysis` flag has been removed from the compiler as well. - [Unaligned references to packed fields are now a hard error.] (rust-lang/rust#102513) This has been a warning since 1.53, and denied by default with a future-compatibility warning since 1.62. - [Update the minimum external LLVM to 14.] (rust-lang/rust#107573) - [Cargo now emits errors on invalid characters in a registry token.] (rust-lang/cargo#11600) - [When `default-features` is set to false of a workspace dependency, and an inherited dependency of a member has `default-features = true`, Cargo will enable default features of that dependency.] (rust-lang/cargo#11409) - [Cargo denies `CARGO_HOME` in the `[env]` configuration table. Cargo itself doesn't pick up this value, but recursive calls to cargo would, which was not intended.] (rust-lang/cargo#11644) - [Debuginfo for build dependencies is now off if not explicitly set. This is expected to improve the overall build time.] (rust-lang/cargo#11252) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Move `format_args!()` into AST (and expand it during AST lowering)] (rust-lang/rust#106745)

rustbot assigned compiler-errors Dec 5, 2022

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 Dec 5, 2022

aliemjay mentioned this pull request Dec 5, 2022

make member constraints pick static if no upper bounds #89056

Closed

This comment was marked as resolved.

Sign in to view

rustbot assigned oli-obk and unassigned compiler-errors Dec 7, 2022

This comment has been minimized.

Sign in to view

aliemjay force-pushed the member-lower branch from ebc767b to 1b74cdc Compare January 15, 2023 22:33

This comment has been minimized.

Sign in to view

rework min_choice algorithm of member constraints

837c1af

See the inline comments for the description of the new algorithm.

aliemjay force-pushed the member-lower branch from 1b74cdc to 837c1af Compare January 17, 2023 15:39

rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Jan 18, 2023

Swatinem mentioned this pull request Jan 30, 2023

Remove identity_future indirection/hack #104826

Closed

rfcbot added the final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. label Feb 2, 2023

This comment was marked as resolved.

Sign in to view

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 Feb 4, 2023

This comment was marked as resolved.

Sign in to view

bors 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-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Feb 4, 2023

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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Feb 13, 2023

Dylan-DPC mentioned this pull request Feb 14, 2023

Rollup of 8 pull requests #108027

Closed

Dylan-DPC mentioned this pull request Feb 15, 2023

Rollup of 7 pull requests #108070

Merged

bors merged commit 83f10ea into rust-lang:master Feb 15, 2023

rustbot added this to the 1.69.0 milestone Feb 15, 2023

aliemjay deleted the member-lower branch February 15, 2023 13:43

Swatinem mentioned this pull request Feb 15, 2023

Remove identity_future indirection #104833

Merged

apiraino removed the to-announce Announce this issue on triage meeting label Feb 16, 2023

compiler-errors mentioned this pull request Aug 8, 2023

Incorrect lifetime bound check in async + impl_trait_in_assoc_type #114572

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

rework min_choice algorithm of member constraints #105300

rework min_choice algorithm of member constraints #105300

aliemjay commented Dec 5, 2022 •

edited

Loading

This comment was marked as resolved.

This comment was marked as resolved.

compiler-errors commented Dec 7, 2022

bors commented Dec 15, 2022

c410-f3r commented Dec 15, 2022

This comment has been minimized.

oli-obk commented Jan 10, 2023

This comment has been minimized.

oli-obk commented Jan 16, 2023

aliemjay commented Jan 16, 2023

compiler-errors commented Jan 18, 2023

rfcbot commented Jan 18, 2023 •

edited by spastorino

Loading

Swatinem commented Jan 30, 2023

oli-obk commented Feb 4, 2023

bors commented Feb 4, 2023

This comment was marked as resolved.

This comment was marked as resolved.

rfcbot commented Feb 12, 2023

aliemjay commented Feb 13, 2023

bors commented Feb 13, 2023

rework min_choice algorithm of member constraints #105300

rework min_choice algorithm of member constraints #105300

Conversation

aliemjay commented Dec 5, 2022 • edited Loading

This comment was marked as resolved.

This comment was marked as resolved.

compiler-errors commented Dec 7, 2022

bors commented Dec 15, 2022

c410-f3r commented Dec 15, 2022

This comment has been minimized.

oli-obk commented Jan 10, 2023

This comment has been minimized.

oli-obk commented Jan 16, 2023

aliemjay commented Jan 16, 2023

Forward compatibility

Implementation

compiler-errors commented Jan 18, 2023

rfcbot commented Jan 18, 2023 • edited by spastorino Loading

Swatinem commented Jan 30, 2023

oli-obk commented Feb 4, 2023

bors commented Feb 4, 2023

This comment was marked as resolved.

This comment was marked as resolved.

rfcbot commented Feb 12, 2023

aliemjay commented Feb 13, 2023

bors commented Feb 13, 2023

aliemjay commented Dec 5, 2022 •

edited

Loading

rfcbot commented Jan 18, 2023 •

edited by spastorino

Loading