change method resolution to constrain hidden types instead of rejecting method candidates #123962

oli-obk · 2024-04-15T11:48:49Z

Some of these are in probes and may affect inference. This is therefore a breaking change.

This allows new code to compile on stable:

trait Trait {}

impl Trait for u32 {}

struct Bar<T>(T);

impl Bar<u32> {
    fn foo(self) {}
}

fn foo(x: bool) -> Bar<impl Sized> {
    if x {
        let x = foo(false);
        x.foo();
        //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so
    }
    todo!()
}

r? @compiler-errors

fixes #121404

cc #116652

Method resolution constrains hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? `@compiler-errors`

oli-obk · 2024-04-15T11:53:09Z

@rfcbot merge

This allows new code to compile on stable. It is a necessary step towards making the old solver more similar to the new solver (and subsequently unblocking stabilizing impl-trait-in-associated-types). See the PR's main post for an example of the new kind of code that is now accepted

rfcbot · 2024-04-15T11:53:11Z

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

Concerns:

~~unexpected-self-constraint~~ resolved by change method resolution to constrain hidden types instead of rejecting method candidates #123962 (comment)

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.

compiler-errors · 2024-04-15T12:43:11Z

This causes (TAIT) code to break, like what caused that CI failure. Pls update the FCP to include an example of what becomes ambiguous during method probe.

lcnr

please also add a revision for -Znext-solver to the added tests

tests/ui/impl-trait/method-resolution.rs

tests/ui/impl-trait/method-resolution2.rs

tests/ui/impl-trait/method-resolution3.rs

lcnr · 2024-04-15T15:58:10Z

tests/ui/type-alias-impl-trait/method_resolution.rs

@@ -0,0 +1,29 @@
+//! check that we do not unify `Bar<Foo>` with `BAr<u32>`, even though the


Suggested change

//! check that we do not unify `Bar<Foo>` with `BAr<u32>`, even though the

//! check that we do not unify `Bar<Foo>` with `Bar<u32>`, even though the

not resolved, also this comment feels outdated 🤔 isn't the cause here that the Bar<u32> impl does not define Foo?

I added more tests to cover the case where it actually defines Foo

tests/ui/type-alias-impl-trait/method_resolution.rs

tests/ui/type-alias-impl-trait/method_resolution2.rs

jackh726 · 2024-04-15T17:07:22Z

But it is also a breaking change, since &self and &mut self method calls on recursive RPIT function calls now constrain the hidden type to &_ and &mut _ respectively. This is not what users really expect or want from this, but there's way around this.

This is concerning to me and I would prefer us to outright error of ambiguity here than constrain incorrectly.

oli-obk · 2024-04-15T17:37:33Z

This is concerning to me and I would prefer us to outright error of ambiguity here than constrain incorrectly.

That's not easy to do in the old solver, and likely impossible to do without major downsides. While we could attempt to move the initial method probing into a canonical query, that would mess with inference as we would not have access to the trait bounds on infer vars anymore.

Note that ne new solver handles this correctly

oli-obk · 2024-04-15T18:10:03Z

@bors try

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` But it is also a breaking change, since `&self` and `&mut self` method calls on recursive RPIT function calls now constrain the hidden type to `&_` and `&mut _` respectively. This is not what users really expect or want from this, but there's way around this. r? `@compiler-errors` fixes rust-lang#121404 cc rust-lang#116652

bors · 2024-04-15T18:11:15Z

⌛ Trying commit af980d5 with merge fe30d25...

jackh726 · 2024-04-15T19:05:55Z

This is concerning to me and I would prefer us to outright error of ambiguity here than constrain incorrectly.

That's not easy to do in the old solver, and likely impossible to do without major downsides. While we could attempt to move the initial method probing into a canonical query, that would mess with inference as we would not have access to the trait bounds on infer vars anymore.

Note that ne new solver handles this correctly

The test I'm focusing on here is tests/ui/impl-trait/method-resolution4.rs. Today, this works exactly as I would expect on stable. With both this PR and with -Znext-solver, it fails. So, this is not a case where I think the new solver behaves as expected. (Similar with tests/ui/type-alias-impl-trait/method_resolution_trait_method_from_opaque.rs).

The problem I have is: if we make this change and break these cases today, we can't in the future unbreak these cases in the future in a backwards-compatible manner I think, even though as we've both said this is not what users expect.

I think it would be good if you can make a separate PR just adding the tests, so we can more clearly see what would be changing in the future.

jackh726 · 2024-04-15T19:08:13Z

I actually do feel strongly about this, so I'm going to go ahead and raise a concern.

@rfcbot concern unexpected-self-constraint

bors · 2024-04-15T19:48:17Z

☀️ Try build successful - checks-actions
Build commit: fe30d25 (fe30d255593ff5176e4ada5fb82b6b6276de3f85)

oli-obk · 2024-04-15T19:56:11Z

@craterbot check

craterbot · 2024-04-15T19:56:22Z

👌 Experiment pr-123962 created and queued.
🤖 Automatically detected try build fe30d25
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

oli-obk · 2024-06-13T10:43:19Z

@bors r=lcnr

bors · 2024-06-13T10:43:21Z

📌 Commit 9cf60ee has been approved by lcnr

It is now in the queue for this repository.

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? `@compiler-errors` fixes rust-lang#121404 cc rust-lang#116652

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? ``@compiler-errors`` fixes rust-lang#121404 cc rust-lang#116652

…iaskrgr Rollup of 7 pull requests Successful merges: - rust-lang#121216 (Always emit `native-static-libs` note, even if it is empty) - rust-lang#122613 (Don't build a broken/untested profiler runtime on mingw targets) - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126343 (Remove some msys2 utils) - rust-lang#126351 (std::unix::fs::link using direct linkat call for Solaris.) - rust-lang#126399 (extend the check for LLVM build) Failed merges: - rust-lang#126388 (const-eval: make lint scope computation consistent) r? `@ghost` `@rustbot` modify labels: rollup

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? ```@compiler-errors``` fixes rust-lang#121404 cc rust-lang#116652

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#121216 (Always emit `native-static-libs` note, even if it is empty) - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#126285 (`UniqueRc`: support allocators and `T: ?Sized`.) - rust-lang#126315 (Add pub struct with allow(dead_code) into worklist) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126343 (Remove some msys2 utils) - rust-lang#126351 (std::unix::fs::link using direct linkat call for Solaris.) - rust-lang#126399 (extend the check for LLVM build) r? `@ghost` `@rustbot` modify labels: rollup

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? ````@compiler-errors```` fixes rust-lang#121404 cc rust-lang#116652

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#121216 (Always emit `native-static-libs` note, even if it is empty) - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#126285 (`UniqueRc`: support allocators and `T: ?Sized`.) - rust-lang#126315 (Add pub struct with allow(dead_code) into worklist) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126343 (Remove some msys2 utils) - rust-lang#126351 (std::unix::fs::link using direct linkat call for Solaris.) - rust-lang#126399 (extend the check for LLVM build) - rust-lang#126436 (Reduce rustdoc GUI tests flakyness) r? `@ghost` `@rustbot` modify labels: rollup

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? `````@compiler-errors````` fixes rust-lang#121404 cc rust-lang#116652

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#121216 (Always emit `native-static-libs` note, even if it is empty) - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#126285 (`UniqueRc`: support allocators and `T: ?Sized`.) - rust-lang#126315 (Add pub struct with allow(dead_code) into worklist) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126343 (Remove some msys2 utils) - rust-lang#126351 (std::unix::fs::link using direct linkat call for Solaris.) - rust-lang#126399 (extend the check for LLVM build) r? `@ghost` `@rustbot` modify labels: rollup

change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? ``````@compiler-errors`````` fixes rust-lang#121404 cc rust-lang#116652

…iaskrgr Rollup of 10 pull requests Successful merges: - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#124884 (place explicit lifetime bound after generic param) - rust-lang#126244 (Update fuchsia commit, and SDK to 21.20240610.2.1) - rust-lang#126270 (Migrate run make const fn mir) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126343 (Remove some msys2 utils) - rust-lang#126351 (std::unix::fs::link using direct linkat call for Solaris.) - rust-lang#126368 (Remove some unnecessary crate dependencies.) - rust-lang#126386 (Migrate `run-make/allow-non-lint-warnings-cmdline` to `rmake.rs`) - rust-lang#126449 (Fill out missing Windows support information) r? `@ghost` `@rustbot` modify labels: rollup

…iaskrgr Rollup of 5 pull requests Successful merges: - rust-lang#123962 (change method resolution to constrain hidden types instead of rejecting method candidates) - rust-lang#126244 (Update fuchsia commit, and SDK to 21.20240610.2.1) - rust-lang#126270 (Migrate run make const fn mir) - rust-lang#126320 (Avoid ICES after reporting errors on erroneous patterns) - rust-lang#126449 (Fill out missing Windows support information) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of rust-lang#123962 - oli-obk:define_opaque_types5, r=lcnr change method resolution to constrain hidden types instead of rejecting method candidates Some of these are in probes and may affect inference. This is therefore a breaking change. This allows new code to compile on stable: ```rust trait Trait {} impl Trait for u32 {} struct Bar<T>(T); impl Bar<u32> { fn foo(self) {} } fn foo(x: bool) -> Bar<impl Sized> { if x { let x = foo(false); x.foo(); //^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so } todo!() } ``` r? ```````@compiler-errors``````` fixes rust-lang#121404 cc rust-lang#116652

This MR contains the following updates: | Package | Update | Change | |---|---|---| | [rust](https://github.com/rust-lang/rust) | minor | `1.80.1` -> `1.81.0` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>rust-lang/rust (rust)</summary> ### [`v1.81.0`](https://github.com/rust-lang/rust/blob/HEAD/RELEASES.md#Version-1810-2024-09-05) [Compare Source](rust-lang/rust@1.80.1...1.81.0) \========================== <a id="1.81.0-Language"></a> ## Language - [Abort on uncaught panics in `extern "C"` functions.](rust-lang/rust#116088) - [Fix ambiguous cases of multiple `&` in elided self lifetimes.](rust-lang/rust#117967) - [Stabilize `#[expect]` for lints (RFC 2383),](rust-lang/rust#120924) like `#[allow]` with a warning if the lint is *not* fulfilled. - [Change method resolution to constrain hidden types instead of rejecting method candidates.](rust-lang/rust#123962) - [Bump `elided_lifetimes_in_associated_constant` to deny.](rust-lang/rust#124211) - [`offset_from`: always allow pointers to point to the same address.](rust-lang/rust#124921) - [Allow constraining opaque types during subtyping in the trait system.](rust-lang/rust#125447) - [Allow constraining opaque types during various unsizing casts.](rust-lang/rust#125610) - [Deny keyword lifetimes pre-expansion.](rust-lang/rust#126762) <a id="1.81.0-Compiler"></a> ## Compiler - [Make casts of pointers to trait objects stricter.](rust-lang/rust#120248) - [Check alias args for well-formedness even if they have escaping bound vars.](rust-lang/rust#123737) - [Deprecate no-op codegen option `-Cinline-threshold=...`.](rust-lang/rust#124712) - [Re-implement a type-size based limit.](rust-lang/rust#125507) - [Properly account for alignment in `transmute` size checks.](rust-lang/rust#125740) - [Remove the `box_pointers` lint.](rust-lang/rust#126018) - [Ensure the interpreter checks bool/char for validity when they are used in a cast.](rust-lang/rust#126265) - [Improve coverage instrumentation for functions containing nested items.](rust-lang/rust#127199) - Target changes: - [Add Tier 3 `no_std` Xtensa targets:](rust-lang/rust#125141) `xtensa-esp32-none-elf`, `xtensa-esp32s2-none-elf`, `xtensa-esp32s3-none-elf` - [Add Tier 3 `std` Xtensa targets:](rust-lang/rust#126380) `xtensa-esp32-espidf`, `xtensa-esp32s2-espidf`, `xtensa-esp32s3-espidf` - [Add Tier 3 i686 Redox OS target:](rust-lang/rust#126192) `i686-unknown-redox` - [Promote `arm64ec-pc-windows-msvc` to Tier 2.](rust-lang/rust#126039) - [Promote `loongarch64-unknown-linux-musl` to Tier 2 with host tools.](rust-lang/rust#126298) - [Enable full tools and profiler for LoongArch Linux targets.](rust-lang/rust#127078) - [Unconditionally warn on usage of `wasm32-wasi`.](rust-lang/rust#126662) (see compatibility note below) - Refer to Rust's \[platform support page]\[platform-support-doc] for more information on Rust's tiered platform support. <a id="1.81.0-Libraries"></a> ## Libraries - [Split core's `PanicInfo` and std's `PanicInfo`.](rust-lang/rust#115974) (see compatibility note below) - [Generalize `{Rc,Arc}::make_mut()` to unsized types.](rust-lang/rust#116113) - [Replace sort implementations with stable `driftsort` and unstable `ipnsort`.](rust-lang/rust#124032) All `slice::sort*` and `slice::select_nth*` methods are expected to see significant performance improvements. See the [research project](https://github.com/Voultapher/sort-research-rs) for more details. - [Document behavior of `create_dir_all` with respect to empty paths.](rust-lang/rust#125112) - [Fix interleaved output in the default panic hook when multiple threads panic simultaneously.](rust-lang/rust#127397) <a id="1.81.0-Stabilized-APIs"></a> ## Stabilized APIs - [`core::error`](https://doc.rust-lang.org/stable/core/error/index.html) - [`hint::assert_unchecked`](https://doc.rust-lang.org/stable/core/hint/fn.assert_unchecked.html) - [`fs::exists`](https://doc.rust-lang.org/stable/std/fs/fn.exists.html) - [`AtomicBool::fetch_not`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicBool.html#method.fetch_not) - [`Duration::abs_diff`](https://doc.rust-lang.org/stable/core/time/struct.Duration.html#method.abs_diff) - [`IoSlice::advance`](https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance) - [`IoSlice::advance_slices`](https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance_slices) - [`IoSliceMut::advance`](https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance) - [`IoSliceMut::advance_slices`](https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance_slices) - [`PanicHookInfo`](https://doc.rust-lang.org/stable/std/panic/struct.PanicHookInfo.html) - [`PanicInfo::message`](https://doc.rust-lang.org/stable/core/panic/struct.PanicInfo.html#method.message) - [`PanicMessage`](https://doc.rust-lang.org/stable/core/panic/struct.PanicMessage.html) These APIs are now stable in const contexts: - [`char::from_u32_unchecked`](https://doc.rust-lang.org/stable/core/char/fn.from_u32\_unchecked.html) (function) - [`char::from_u32_unchecked`](https://doc.rust-lang.org/stable/core/primitive.char.html#method.from_u32\_unchecked) (method) - [`CStr::count_bytes`](https://doc.rust-lang.org/stable/core/ffi/c_str/struct.CStr.html#method.count_bytes) - [`CStr::from_ptr`](https://doc.rust-lang.org/stable/core/ffi/c_str/struct.CStr.html#method.from_ptr) <a id="1.81.0-Cargo"></a> ## Cargo - [Generated `.cargo_vcs_info.json` is always included, even when `--allow-dirty` is passed.](rust-lang/cargo#13960) - [Disallow `package.license-file` and `package.readme` pointing to non-existent files during packaging.](rust-lang/cargo#13921) - [Disallow passing `--release`/`--debug` flag along with the `--profile` flag.](rust-lang/cargo#13971) - [Remove `lib.plugin` key support in `Cargo.toml`. Rust plugin support has been deprecated for four years and was removed in 1.75.0.](rust-lang/cargo#13902) <a id="1.81.0-Compatibility-Notes"></a> ## Compatibility Notes - Usage of the `wasm32-wasi` target will now issue a compiler warning and request users switch to the `wasm32-wasip1` target instead. Both targets are the same, `wasm32-wasi` is only being renamed, and this [change to the WASI target](https://blog.rust-lang.org/2024/04/09/updates-to-rusts-wasi-targets.html) is being done to enable removing `wasm32-wasi` in January 2025. - We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0. `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*. The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`. - The new sort implementations may panic if a type's implementation of [`Ord`](https://doc.rust-lang.org/std/cmp/trait.Ord.html) (or the given comparison function) does not implement a [total order](https://en.wikipedia.org/wiki/Total_order) as the trait requires. `Ord`'s supertraits (`PartialOrd`, `Eq`, and `PartialEq`) must also be consistent. The previous implementations would not "notice" any problem, but the new implementations have a good chance of detecting inconsistencies, throwing a panic rather than returning knowingly unsorted data. - [In very rare cases, a change in the internal evaluation order of the trait solver may result in new fatal overflow errors.](rust-lang/rust#126128) <a id="1.81.0-Internal-Changes"></a> ## 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. - [Add a Rust-for Linux `auto` CI job to check kernel builds.](rust-lang/rust#125209) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this MR, check this box --- This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).

Pkgsrc changes: * Adapt patches, apply to new vendored crates where needed. * Back-port rust pull request 130110, "make dist vendoring configurable" * Disable "dist vendoring", otherwise cargo would try to access the network during the build phase. Upstream changes: Version 1.81.0 (2024-09-05) ========================== Language -------- - [Abort on uncaught panics in `extern "C"` functions.] (rust-lang/rust#116088) - [Fix ambiguous cases of multiple `&` in elided self lifetimes.] (rust-lang/rust#117967) - [Stabilize `#[expect]` for lints (RFC 2383),] (rust-lang/rust#120924) like `#[allow]` with a warning if the lint is _not_ fulfilled. - [Change method resolution to constrain hidden types instead of rejecting method candidates.] (rust-lang/rust#123962) - [Bump `elided_lifetimes_in_associated_constant` to deny.] (rust-lang/rust#124211) - [`offset_from`: always allow pointers to point to the same address.] (rust-lang/rust#124921) - [Allow constraining opaque types during subtyping in the trait system.] (rust-lang/rust#125447) - [Allow constraining opaque types during various unsizing casts.] (rust-lang/rust#125610) - [Deny keyword lifetimes pre-expansion.] (rust-lang/rust#126762) Compiler -------- - [Make casts of pointers to trait objects stricter.] (rust-lang/rust#120248) - [Check alias args for well-formedness even if they have escaping bound vars.] (rust-lang/rust#123737) - [Deprecate no-op codegen option `-Cinline-threshold=...`.] (rust-lang/rust#124712) - [Re-implement a type-size based limit.] (rust-lang/rust#125507) - [Properly account for alignment in `transmute` size checks.] (rust-lang/rust#125740) - [Remove the `box_pointers` lint.] (rust-lang/rust#126018) - [Ensure the interpreter checks bool/char for validity when they are used in a cast.] (rust-lang/rust#126265) - [Improve coverage instrumentation for functions containing nested items.] (rust-lang/rust#127199) - Target changes: - [Add Tier 3 `no_std` Xtensa targets:] (rust-lang/rust#125141) `xtensa-esp32-none-elf`, `xtensa-esp32s2-none-elf`, `xtensa-esp32s3-none-elf` - [Add Tier 3 `std` Xtensa targets:] (rust-lang/rust#126380) `xtensa-esp32-espidf`, `xtensa-esp32s2-espidf`, `xtensa-esp32s3-espidf` - [Add Tier 3 i686 Redox OS target:] (rust-lang/rust#126192) `i686-unknown-redox` - [Promote `arm64ec-pc-windows-msvc` to Tier 2.] (rust-lang/rust#126039) - [Promote `wasm32-wasip2` to Tier 2.] (rust-lang/rust#126967) - [Promote `loongarch64-unknown-linux-musl` to Tier 2 with host tools.] (rust-lang/rust#126298) - [Enable full tools and profiler for LoongArch Linux targets.] (rust-lang/rust#127078) - [Unconditionally warn on usage of `wasm32-wasi`.] (rust-lang/rust#126662) (see compatibility note below) - Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Split core's `PanicInfo` and std's `PanicInfo`.] (rust-lang/rust#115974) (see compatibility note below) - [Generalize `{Rc,Arc}::make_mut()` to unsized types.] (rust-lang/rust#116113) - [Replace sort implementations with stable `driftsort` and unstable `ipnsort`.] (rust-lang/rust#124032) All `slice::sort*` and `slice::select_nth*` methods are expected to see significant performance improvements. See the [research project] (https://github.com/Voultapher/sort-research-rs) for more details. - [Document behavior of `create_dir_all` with respect to empty paths.] (rust-lang/rust#125112) - [Fix interleaved output in the default panic hook when multiple threads panic simultaneously.] (rust-lang/rust#127397) - Fix `Command`'s batch files argument escaping not working when file name has trailing whitespace or periods (CVE-2024-43402). Stabilized APIs --------------- - [`core::error`] (https://doc.rust-lang.org/stable/core/error/index.html) - [`hint::assert_unchecked`] (https://doc.rust-lang.org/stable/core/hint/fn.assert_unchecked.html) - [`fs::exists`] (https://doc.rust-lang.org/stable/std/fs/fn.exists.html) - [`AtomicBool::fetch_not`] (https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicBool.html#method.fetch_not) - [`Duration::abs_diff`] (https://doc.rust-lang.org/stable/core/time/struct.Duration.html#method.abs_diff) - [`IoSlice::advance`] (https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance) - [`IoSlice::advance_slices`] (https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance_slices) - [`IoSliceMut::advance`] (https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance) - [`IoSliceMut::advance_slices`] (https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance_slices) - [`PanicHookInfo`] (https://doc.rust-lang.org/stable/std/panic/struct.PanicHookInfo.html) - [`PanicInfo::message`] (https://doc.rust-lang.org/stable/core/panic/struct.PanicInfo.html#method.message) - [`PanicMessage`] (https://doc.rust-lang.org/stable/core/panic/struct.PanicMessage.html) These APIs are now stable in const contexts: - [`char::from_u32_unchecked`] (https://doc.rust-lang.org/stable/core/char/fn.from_u32_unchecked.html) (function) - [`char::from_u32_unchecked`] (https://doc.rust-lang.org/stable/core/primitive.char.html#method.from_u32_unchecked) (method) - [`CStr::count_bytes`] (https://doc.rust-lang.org/stable/core/ffi/c_str/struct.CStr.html#method.count_bytes) - [`CStr::from_ptr`] (https://doc.rust-lang.org/stable/core/ffi/c_str/struct.CStr.html#method.from_ptr) Cargo ----- - [Generated `.cargo_vcs_info.json` is always included, even when `--allow-dirty` is passed.] (rust-lang/cargo#13960) - [Disallow `package.license-file` and `package.readme` pointing to non-existent files during packaging.] (rust-lang/cargo#13921) - [Disallow passing `--release`/`--debug` flag along with the `--profile` flag.] (rust-lang/cargo#13971) - [Remove `lib.plugin` key support in `Cargo.toml`. Rust plugin support has been deprecated for four years and was removed in 1.75.0.] (rust-lang/cargo#13902) Compatibility Notes ------------------- * Usage of the `wasm32-wasi` target will now issue a compiler warning and request users switch to the `wasm32-wasip1` target instead. Both targets are the same, `wasm32-wasi` is only being renamed, and this [change to the WASI target] (https://blog.rust-lang.org/2024/04/09/updates-to-rusts-wasi-targets.html) is being done to enable removing `wasm32-wasi` in January 2025. * We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0. `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*. The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`. * The new sort implementations may panic if a type's implementation of [`Ord`](https://doc.rust-lang.org/std/cmp/trait.Ord.html) (or the given comparison function) does not implement a [total order](https://en.wikipedia.org/wiki/Total_order) as the trait requires. `Ord`'s supertraits (`PartialOrd`, `Eq`, and `PartialEq`) must also be consistent. The previous implementations would not "notice" any problem, but the new implementations have a good chance of detecting inconsistencies, throwing a panic rather than returning knowingly unsorted data. * [In very rare cases, a change in the internal evaluation order of the trait solver may result in new fatal overflow errors.] (rust-lang/rust#126128) 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. - [Add a Rust-for Linux `auto` CI job to check kernel builds.] (rust-lang/rust#125209)

oli-obk added the T-types Relevant to the types team, which will review and decide on the PR/issue. label Apr 15, 2024

rustbot assigned compiler-errors Apr 15, 2024

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Apr 15, 2024

This comment was marked as outdated.

Sign in to view

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 Apr 15, 2024

oli-obk force-pushed the define_opaque_types5 branch from a6c6b29 to 2538276 Compare April 15, 2024 11:54

This comment was marked as resolved.

Sign in to view

lcnr changed the title ~~Method resolution constrains hidden types instead of rejecting method candidates~~ change method resolution to constrain hidden types instead of rejecting method candidates Apr 15, 2024

lcnr reviewed Apr 15, 2024

View reviewed changes

oli-obk force-pushed the define_opaque_types5 branch from 2538276 to af980d5 Compare April 15, 2024 15:11

lcnr reviewed Apr 15, 2024

View reviewed changes

tests/ui/type-alias-impl-trait/method_resolution.rs Outdated Show resolved Hide resolved

lcnr reviewed Apr 15, 2024

View reviewed changes

tests/ui/type-alias-impl-trait/method_resolution2.rs Outdated Show resolved Hide resolved

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 Jun 13, 2024

fmease mentioned this pull request Jun 13, 2024

Rollup of 5 pull requests #126397

Closed

matthiaskrgr mentioned this pull request Jun 13, 2024

Rollup of 7 pull requests #126412

Closed

matthiaskrgr mentioned this pull request Jun 13, 2024

Rollup of 8 pull requests #126433

Closed

matthiaskrgr mentioned this pull request Jun 13, 2024

Rollup of 9 pull requests #126438

Closed

matthiaskrgr mentioned this pull request Jun 13, 2024

Rollup of 8 pull requests #126441

Closed

matthiaskrgr mentioned this pull request Jun 14, 2024

Rollup of 10 pull requests #126458

Closed

matthiaskrgr mentioned this pull request Jun 14, 2024

Rollup of 5 pull requests #126462

Merged

bors merged commit 0468462 into rust-lang:master Jun 14, 2024
6 checks passed

rustbot added this to the 1.81.0 milestone Jun 14, 2024

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

change method resolution to constrain hidden types instead of rejecting method candidates #123962

change method resolution to constrain hidden types instead of rejecting method candidates #123962

oli-obk commented Apr 15, 2024 •

edited

Loading

This comment was marked as outdated.

This comment was marked as outdated.

oli-obk commented Apr 15, 2024

rfcbot commented Apr 15, 2024 •

edited by BoxyUwU

Loading

This comment was marked as resolved.

This comment was marked as resolved.

compiler-errors commented Apr 15, 2024

lcnr left a comment

lcnr Apr 15, 2024

lcnr Jun 13, 2024 •

edited

Loading

oli-obk Jun 13, 2024

jackh726 commented Apr 15, 2024

oli-obk commented Apr 15, 2024 •

edited

Loading

oli-obk commented Apr 15, 2024

bors commented Apr 15, 2024

jackh726 commented Apr 15, 2024 •

edited

Loading

jackh726 commented Apr 15, 2024

bors commented Apr 15, 2024

oli-obk commented Apr 15, 2024

craterbot commented Apr 15, 2024

oli-obk commented Jun 13, 2024

bors commented Jun 13, 2024

		@@ -0,0 +1,29 @@
		//! check that we do not unify `Bar<Foo>` with `BAr<u32>`, even though the

change method resolution to constrain hidden types instead of rejecting method candidates #123962

change method resolution to constrain hidden types instead of rejecting method candidates #123962

Conversation

oli-obk commented Apr 15, 2024 • edited Loading

This comment was marked as outdated.

This comment was marked as outdated.

oli-obk commented Apr 15, 2024

rfcbot commented Apr 15, 2024 • edited by BoxyUwU Loading

This comment was marked as resolved.

This comment was marked as resolved.

compiler-errors commented Apr 15, 2024

lcnr left a comment

Choose a reason for hiding this comment

lcnr Apr 15, 2024

Choose a reason for hiding this comment

lcnr Jun 13, 2024 • edited Loading

Choose a reason for hiding this comment

oli-obk Jun 13, 2024

Choose a reason for hiding this comment

jackh726 commented Apr 15, 2024

oli-obk commented Apr 15, 2024 • edited Loading

oli-obk commented Apr 15, 2024

bors commented Apr 15, 2024

jackh726 commented Apr 15, 2024 • edited Loading

jackh726 commented Apr 15, 2024

bors commented Apr 15, 2024

oli-obk commented Apr 15, 2024

craterbot commented Apr 15, 2024

oli-obk commented Jun 13, 2024

bors commented Jun 13, 2024

oli-obk commented Apr 15, 2024 •

edited

Loading

rfcbot commented Apr 15, 2024 •

edited by BoxyUwU

Loading

lcnr Jun 13, 2024 •

edited

Loading

oli-obk commented Apr 15, 2024 •

edited

Loading

jackh726 commented Apr 15, 2024 •

edited

Loading