Constify trait aliases
Allow `const trait Foo = Bar + [const] Baz;` trait alias declarations. Their rules are the same as with super traits of const traits. So `[const] Baz` or `const Baz` is only required for `[const] Foo` or `const Foo` bounds respectively.
tracking issue rust-lang/rust#41517 (part of the general trait alias feature gate, but I can split it out into a separate const trait alias feature gate. I just assumed that const traits would stabilize before trait aliases, and we'd want to stabilize trait aliases together with const trait aliases at the same time)
r? ``@compiler-errors`` ``@fee1-dead``
Mark desugared range expression spans with DesugaringKind::RangeExpr
This is a prerequisite to removing `QPath::LangItem` (rust-lang/rust#115178) because otherwise there would be no way to detect a range expression in the HIR.
There are some non-obvious Clippy changes so a Clippy team review would be good.
Add NonNull pattern types
These are the final piece missing for
* https://github.com/rust-lang/rust/pull/136006
We cannot use the previous scheme of using an integer range for raw pointers, as we're not just changing the layout of raw pointers anymore, but also the type representation. And we can't represent "any provenance or NonZero<usize>" natively as patterns. So I created a new `!null` pattern. Since this is all unstable representation stuff for replacing rustc_layout_scalar_range_start with pattern types, the divergence from normal patterns is fine, especially since T-lang seems interested in exploring general negation patterns
r? `@BoxyUwU`
Rollup of 11 pull requests
Successful merges:
- rust-lang/rust#143191 (Stabilize `rwlock_downgrade` library feature)
- rust-lang/rust#147444 (Allow printing a fully-qualified path in `def_path_str`)
- rust-lang/rust#147527 (Update t-compiler beta nomination Zulip msg)
- rust-lang/rust#147670 (some `ErrorGuaranteed` cleanups)
- rust-lang/rust#147676 (Return spans out of `is_doc_comment` to reduce reliance on `.span()` on attributes)
- rust-lang/rust#147708 (const `mem::drop`)
- rust-lang/rust#147710 (Fix ICE when using contracts on async functions)
- rust-lang/rust#147716 (Fix some comments)
- rust-lang/rust#147718 (miri: use allocator_shim_contents codegen helper)
- rust-lang/rust#147729 (ignore boring locals when explaining why a borrow contains a point due to drop of a live local under polonius)
- rust-lang/rust#147742 (Revert unintentional whitespace changes to rustfmt-excluded file)
r? `@ghost`
`@rustbot` modify labels: rollup
No longer require that we prove that the predicates of aliases hold when
checking the well-formedness of the alias. This permits more uses of GATs
and changes the output of yet more tests.
For sizedness, default and auto trait predicates, now prefer non-param
candidates if any exist. As these traits do not have generic parameters,
it never makes sense to prefer an non-alias candidate, as there can
never be a more permissive candidate.
Split overlapping_{inherent,trait}_impls
This yielded some perf improvement for me. Reduces some calls to `impl_trait_header` query. But I think the llvm optimization is more relevant.
Prefer to use repeat_n over repeat().take()
More from https://github.com/rust-lang/rust/pull/147464, but batch processed with `ast-grep` to find and replace.
second commit add notes for library: affaf532f9
r? ``@RalfJung``
Prevent downstream `impl DerefMut for Pin<LocalType>`
The safety requirements for [`PinCoerceUnsized`](https://doc.rust-lang.org/stable/std/pin/trait.PinCoerceUnsized.html) are essentially that the type does not have a malicious `Deref` or `DerefMut` impl. However, the `Pin` type is fundamental, so the end-user can provide their own implementation of `DerefMut` for `Pin<&SomeLocalType>`, so it's possible for `Pin` to have a malicious `DerefMut` impl. This unsoundness is known as rust-lang/rust#85099.
Unfortunately, this means that the implementation of `PinCoerceUnsized` for `Pin` is currently unsound. To fix that, modify the impl so that it becomes impossible for downstream crates to provide their own implementation of `DerefMut` for `Pin` by abusing a hidden struct that is not fundamental.
This PR is a breaking change, but it fixesrust-lang/rust#85099. The PR supersedes rust-lang/rust#144896.
r? lcnr
compiler: Hint at multiple crate versions if trait impl is for wrong ADT
If a user does e.g.
impl From<Bar> for foo::Foo
and get a compilation error about that `From<Bar>` is not implemented for `Foo`, check if multiple versions of the crate with `Foo` is present in the dependency graph. If so, give a hint about it.
Note that a test is added as a separate commit so it is easy to see what effect the fix has on the emitted error message.
This can be seen as a continuation of rust-lang/rust#124944.
I think this closes RUST-71693 but I haven't checked since it lacks a minimal reproducer. If this gets merged I'll ask that reporter if this fix works for them.
## Real world example
I encountered this case in the wild and didn't realize I had multiple versions of a crate in my dependency graph. So I was a bit confused at first. For reference, here is what that looked like.
<details>
<summary>Click to expand</summary>
### Before fix
```
error[E0277]: the trait bound `lambda_http::lambda_runtime::Diagnostic: From<Error>` is not satisfied
--> src/main.rs:73:5
|
73 | lambda_http::run(service_fn(handle_event)).await
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<Error>` is not implemented for `lambda_http::lambda_runtime::Diagnostic`
|
= help: the following other types implement trait `From<T>`:
`lambda_http::lambda_runtime::Diagnostic` implements `From<&str>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError + Send + Sync>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Infallible>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<lambda_runtime::deserializer::DeserializeError>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::io::Error>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::string::String>`
= note: required for `Error` to implement `Into<lambda_http::lambda_runtime::Diagnostic>`
note: required by a bound in `lambda_http::run`
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_http-0.17.0/src/lib.rs:199:26
|
194 | pub async fn run<'a, R, S, E>(handler: S) -> Result<(), Error>
| --- required by a bound in this function
...
199 | E: std::fmt::Debug + Into<Diagnostic>,
| ^^^^^^^^^^^^^^^^ required by this bound in `run`
error[E0277]: the trait bound `lambda_http::lambda_runtime::Diagnostic: From<Error>` is not satisfied
--> src/main.rs:73:48
|
73 | lambda_http::run(service_fn(handle_event)).await
| ^^^^^ the trait `From<Error>` is not implemented for `lambda_http::lambda_runtime::Diagnostic`
|
= help: the following other types implement trait `From<T>`:
`lambda_http::lambda_runtime::Diagnostic` implements `From<&str>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError + Send + Sync>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Infallible>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<lambda_runtime::deserializer::DeserializeError>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::io::Error>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::string::String>`
= note: required for `Error` to implement `Into<lambda_http::lambda_runtime::Diagnostic>`
note: required by a bound in `lambda_http::run`
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_http-0.17.0/src/lib.rs:199:26
|
194 | pub async fn run<'a, R, S, E>(handler: S) -> Result<(), Error>
| --- required by a bound in this function
...
199 | E: std::fmt::Debug + Into<Diagnostic>,
| ^^^^^^^^^^^^^^^^ required by this bound in `run`
For more information about this error, try `rustc --explain E0277`.
error: could not compile `auto-merge-dependabot-pull-requests-webhook` (bin "auto-merge-dependabot-pull-requests-webhook") due to 2 previous errors
```
### After fix
```
Compiling auto-merge-dependabot-pull-requests-webhook v0.1.0 (/home/martin/src/auto-merge-dependabot-prs/rust-webhook)
error[E0277]: the trait bound `lambda_http::lambda_runtime::Diagnostic: From<Error>` is not satisfied
--> src/main.rs:73:5
|
73 | lambda_http::run(service_fn(handle_event)).await
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<Error>` is not implemented for `lambda_http::lambda_runtime::Diagnostic`
|
help: item with same name found
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_runtime-0.13.0/src/diagnostic.rs:43:1
|
43 | pub struct Diagnostic {
| ^^^^^^^^^^^^^^^^^^^^^
= note: perhaps two different versions of crate `lambda_runtime` are being used?
= help: the following other types implement trait `From<T>`:
`lambda_http::lambda_runtime::Diagnostic` implements `From<&str>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError + Send + Sync>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Infallible>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<lambda_runtime::deserializer::DeserializeError>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::io::Error>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::string::String>`
= note: required for `Error` to implement `Into<lambda_http::lambda_runtime::Diagnostic>`
note: required by a bound in `lambda_http::run`
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_http-0.17.0/src/lib.rs:199:26
|
194 | pub async fn run<'a, R, S, E>(handler: S) -> Result<(), Error>
| --- required by a bound in this function
...
199 | E: std::fmt::Debug + Into<Diagnostic>,
| ^^^^^^^^^^^^^^^^ required by this bound in `run`
error[E0277]: the trait bound `lambda_http::lambda_runtime::Diagnostic: From<Error>` is not satisfied
--> src/main.rs:73:48
|
73 | lambda_http::run(service_fn(handle_event)).await
| ^^^^^ the trait `From<Error>` is not implemented for `lambda_http::lambda_runtime::Diagnostic`
|
help: item with same name found
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_runtime-0.13.0/src/diagnostic.rs:43:1
|
43 | pub struct Diagnostic {
| ^^^^^^^^^^^^^^^^^^^^^
= note: perhaps two different versions of crate `lambda_runtime` are being used?
= help: the following other types implement trait `From<T>`:
`lambda_http::lambda_runtime::Diagnostic` implements `From<&str>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError + Send + Sync>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Box<dyn StdError>>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<Infallible>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<lambda_runtime::deserializer::DeserializeError>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::io::Error>`
`lambda_http::lambda_runtime::Diagnostic` implements `From<std::string::String>`
= note: required for `Error` to implement `Into<lambda_http::lambda_runtime::Diagnostic>`
note: required by a bound in `lambda_http::run`
--> /home/martin/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/lambda_http-0.17.0/src/lib.rs:199:26
|
194 | pub async fn run<'a, R, S, E>(handler: S) -> Result<(), Error>
| --- required by a bound in this function
...
199 | E: std::fmt::Debug + Into<Diagnostic>,
| ^^^^^^^^^^^^^^^^ required by this bound in `run`
For more information about this error, try `rustc --explain E0277`.
error: could not compile `auto-merge-dependabot-pull-requests-webhook` (bin "auto-merge-dependabot-pull-requests-webhook") due to 2 previous errors
```
</details>
try-job: dist-various-1
try-job: aarch64-msvc-1
If a user does e.g.
impl From<Bar> for foo::Foo
and get a compilation error about that `From<Bar>` is not implemented
for `Foo`, check if multiple versions of the crate with `Foo` is present
in the dependency graph. If so, give a hint about it.
I encountered this case in the wild and didn't realize I had multiple
versions of a crate in my dependency graph. So I was a bit confused at
first. This fix will make life easier for others.
remove outdated comment in (inner) `InferCtxt`
This comment seems to have stopped being relevant around 3 years ago after 9f95c605f8. A map? what map? :P
r? `@lcnr`
Fix the bevy implied bounds hack for the next solver
The diff is trivial, of course, and basically what you already suggested. Mostly dug around a bunch to learn. I hope this is roughly what you had in mind.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/236.
r? `@lcnr`
Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics
Fixes https://github.com/rust-lang/rust/issues/132024.
``@rustbot`` label A-diagnostics T-compiler
Rename various "concrete opaque type" things to say "hidden type"
r? lcnr
I've found "concrete opaque type" terminology to be somewhat confusing as in conversation and when explaining opaque type stuff to people I always just talk about things in terms of hidden types. Also the hidden types of opaques are very much not *concrete* in the same sense that a type without any generic parameters is concrete which is an unfortunate overlap in terminology.
I've tried to update comments to also stop referring to things as concrete opaque types but this is mostly best effort as it difficult to find all such cases amongst the massive amounts of uses of "concrete" or "hidden" across the whole compiler.
remove incorrect fast path
Using `tcx.is_copy_modulo_regions` drops information from the current `typing_env`. Writing a regression test for this is really hard. We need to prove `Copy` of something that doesn't directly reference a coroutine or an opaque, but does so indirectly.
cc rust-lang/rust#146813.
