Stabilize the `#[diagnostic]` namespace and `#[diagnostic::on_unimplemented]` attribute
This PR stabilizes the `#[diagnostic]` attribute namespace and a minimal option of the `#[diagnostic::on_unimplemented]` attribute.
The `#[diagnostic]` attribute namespace is meant to provide a home for attributes that allow users to influence error messages emitted by the compiler. The compiler is not guaranteed to use any of this hints, however it should accept any (non-)existing attribute in this namespace and potentially emit lint-warnings for unused attributes and options. This is meant to allow discarding certain attributes/options in the future to allow fundamental changes to the compiler without the need to keep then non-meaningful options working.
The `#[diagnostic::on_unimplemented]` attribute is allowed to appear on a trait definition. This allows crate authors to hint the compiler to emit a specific error message if a certain trait is not implemented. For the `#[diagnostic::on_unimplemented]` attribute the following options are implemented:
* `message` which provides the text for the top level error message
* `label` which provides the text for the label shown inline in the broken code in the error message
* `note` which provides additional notes.
The `note` option can appear several times, which results in several note messages being emitted. If any of the other options appears several times the first occurrence of the relevant option specifies the actually used value. Any other occurrence generates an lint warning. For any other non-existing option a lint-warning is generated.
All three options accept a text as argument. This text is allowed to contain format parameters referring to generic argument or `Self` by name via the `{Self}` or `{NameOfGenericArgument}` syntax. For any non-existing argument a lint warning is generated.
This allows to have a trait definition like:
```rust
#[diagnostic::on_unimplemented(
message = "My Message for `ImportantTrait<{A}>` is not implemented for `{Self}`",
label = "My Label",
note = "Note 1",
note = "Note 2"
)]
trait ImportantTrait<A> {}
```
which then generates for the following code
```rust
fn use_my_trait(_: impl ImportantTrait<i32>) {}
fn main() {
use_my_trait(String::new());
}
```
this error message:
```
error[E0277]: My Message for `ImportantTrait<i32>` is not implemented for `String`
--> src/main.rs:14:18
|
14 | use_my_trait(String::new());
| ------------ ^^^^^^^^^^^^^ My Label
| |
| required by a bound introduced by this call
|
= help: the trait `ImportantTrait<i32>` is not implemented for `String`
= note: Note 1
= note: Note 2
```
[Playground with the unstable feature](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=05133acce8e1d163d481e97631f17536)
Fixes#111996
Rollup of 10 pull requests
Successful merges:
- #121863 (silence mismatched types errors for implied projections)
- #122043 (Apply `EarlyBinder` only to `TraitRef` in `ImplTraitHeader`)
- #122066 (Add proper cfgs for struct HirIdValidator used only with debug-assert)
- #122104 (Rust is a proper name: rust → Rust)
- #122110 (Make `x t miri` respect `MIRI_TEMP`)
- #122114 (Make not finding core a fatal error)
- #122115 (Cancel parsing ever made during recovery)
- #122123 (Don't require specifying unrelated assoc types when trait alias is in `dyn` type)
- #122126 (Fix `tidy --bless` on ̶X̶e̶n̶i̶x̶ Windows)
- #122129 (Set `RustcDocs` to only run on host)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix `tidy --bless` on ̶X̶e̶n̶i̶x̶ Windows
As reported in https://github.com/rust-lang/rust/pull/120628#issuecomment-1973655740 the requested `tidy --bless` implementation didn't take into account the fact that earlier the linting code canonicalized things to use the OS path separator. This makes it so that the path separator is always rewritten back as '/', which should fix the variance there.
r? ``@ChrisDenton``
Don't require specifying unrelated assoc types when trait alias is in `dyn` type
Object types must specify the associated types for all of the principal trait ref's supertraits. However, we weren't doing elaboration properly, so we incorrectly errored with erroneous suggestions to specify associated types that were unrelated to that principal trait ref. To fix this, use proper supertrait elaboration when expanding trait aliases in `conv_object_ty_poly_trait_ref`.
**NOTE**: Please use the ignore-whitespace option when reviewing. This only touches a handful of lines.
r? oli-obk or please feel free to reassign.
Fixes#122118
Make not finding core a fatal error
Similar to https://github.com/rust-lang/rust/pull/120472, this prevents terminal spam. In particular, it makes the good diagnostic visible when you try to use a target that's not installed.
Apply `EarlyBinder` only to `TraitRef` in `ImplTraitHeader`
Resolves#121852
This PR
1. Moves `EarlyBinder` to `TraitRef` inside `ImplTraitHeader`,
2. Changes visibility of `coherence::builtin::check_trait` to `pub(super)` from `pub` as it seems not being re-exported from the `coherence` module.
silence mismatched types errors for implied projections
Currently, if a trait bound is not satisfied, then we suppress any errors for the trait's supertraits not being satisfied, but still report errors for super projections not being satisfied.
For example:
```rust
trait Super {
type Assoc;
}
trait Sub: Super<Assoc = ()> {}
```
Before this PR, if `T: Sub` is not satisfied, then errors for `T: Super` are suppressed, but errors for `<T as Super>::Assoc == ()` are still shown. This PR makes it so that errors about super projections not being satisfied are also suppressed.
The errors are only suppressed if the span of the trait obligation matches the span of the super predicate obligation to avoid silencing error that are not related. This PR removes some differences between the spans of supertraits and super projections to make the suppression work correctly.
This PR fixes the majority of the diagnostics fallout when making `Thin` a supertrait of `Sized` (in a future PR).
cc https://github.com/rust-lang/rust/pull/120354#issuecomment-1930585382
cc `@lcnr`
interpret: avoid a long-lived PlaceTy in stack frames
`PlaceTy` uses a representation that's not very stable under changes to the stack. I'd feel better if we didn't have one in the long-term machine state.
r? `@oli-obk`
Merge `check_mod_impl_wf` and `check_mod_type_wf`
This still causes some funny diagnostics, but I'm not sure they can be fixed without a larger change, which I'd like to avoid here.
Reducing the number of times we iterate over the same items at this high level helps avoid parallel-compiler bottlenecks.
Update cargo
14 commits in f772ec0224d3755ce52ac5128a80319fb2eb45d0..a4c63fe5388beaa09e5f91196c86addab0a03580
2024-03-01 22:57:35 +0000 to 2024-03-06 22:15:17 +0000
- fix(cli): Skip tracing-chrome for platforms without 64bit atomics (rust-lang/cargo#13551)
- chore: downgrade to openssl v1.1.1 (again) (rust-lang/cargo#13550)
- fix(cli): Add traces to clarify where time is going (rust-lang/cargo#13545)
- fix(rustdoc-map): dedup `--extern-html-too-url` for same unit (rust-lang/cargo#13544)
- test: Add test for packaging a public dependency (rust-lang/cargo#13536)
- doc: Edits for git/path dependency sections (rust-lang/cargo#13341)
- feat(cli): Allow logging to chrome traces (rust-lang/cargo#13399)
- fix(log): Trace parameters to align with profile (rust-lang/cargo#13538)
- fix(toml): Don't warn on unset Edition if only 2015 is compatible (rust-lang/cargo#13533)
- fix(cli): Trace core cargo operations (rust-lang/cargo#13532)
- chore: update pulldown-cmark to 0.10.0 (rust-lang/cargo#13517)
- feat(add): Fallback to `rustc -v` when no MSRV is set (rust-lang/cargo#13516)
- chore(ci): Ensure lockfile is respected during MSRV testing (rust-lang/cargo#13523)
- feat: Use consistent colors when testing (rust-lang/cargo#13520)
Rollup of 9 pull requests
Successful merges:
- #121958 (Fix redundant import errors for preload extern crate)
- #121976 (Add an option to have an external download/bootstrap cache)
- #122022 (loongarch: add frecipe and relax target feature)
- #122026 (Do not try to format removed files)
- #122027 (Uplift some feeding out of `associated_type_for_impl_trait_in_impl` and into queries)
- #122063 (Make the lowering of `thir::ExprKind::If` easier to follow)
- #122074 (Add missing PartialOrd trait implementation doc for array)
- #122082 (remove outdated fixme comment)
- #122091 (Note why we're using a new thread in `test_get_os_named_thread`)
r? `@ghost`
`@rustbot` modify labels: rollup
compiletest: Add a `//@ needs-threads` directive
This commit is extracted from #122036 and adds a new directive to the `compiletest` test runner, `//@ needs-threads`. This is intended to capture the need that a target must implement threading to execute a specific test, typically one that uses `std::thread`. This is primarily done for WebAssembly targets which currently do not have threads by default. This enables transitioning a lot of `//@ ignore-wasm*`-style ignores into a more self-documenting `//@ needs-threads` directive. Additionally the `wasm32-wasi-preview1-threads` target, for example, does actually have threads, but isn't tested in CI at this time. This change enables running these tests for that target, but not other wasm targets.
Remove unnecessary fixme on new thread stack size
As the FIXME itself notes, there's nothing to fix here.
And as the documentation for [`CreateThread`] says of `dwStackSize`, the value is rounded up to the nearest page. A 4kb stack is very small but perfectly usable if you're careful. Of course it will be very limited but there's no reason to add artificial limits. We don't know what the user is doing.
[`CreateThread`]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createthread
Refer to "slice" instead of "vector" in Ord and PartialOrd trait impl of slices
The trait implementation comments of Ord and PartialOrd for slice incorrectly mention "vectors" instead of "slices".
This PR fixes those two comments as requested in #122071.
Explicitly assign constructed C++ classes
C++ style guides I am aware of recommend specifically preferring = syntax for any classes with fairly obvious constructors[^0] that do not perform any complicated logic in their constructor. I contend that all constructors that the `rustc_llvm` code uses qualify. This has only become more common since C++ 17 guaranteed many cases of copy initialization elision.
The other detail is that I tried to ask another contributor with infinitely more C++ experience than me (i.e. any) what this constructor syntax was, and they thought it was a macro. I know of no other language that has adopted this same syntax. As the rustc codebase features many contributors experienced in many other languages, using a less... unique... style has many other benefits in making this code more lucid and maintainable, which is something it direly needs.
[^0]: e.g. https://abseil.io/tips/88
Add better explanation for `rustc_index::IndexVec`
I feel like I didn't do a great job explaining what this does in https://github.com/rust-lang/rust/pull/119800, so this PR tries to give an example of why and how you would use it.
Addresses #93792.
Note why we're using a new thread in `test_get_os_named_thread`
``@RalfJung`` expressed some "surprise and confusion" about why we're spawning a new thread in this test. Hopefully this comment will help future readers.
remove outdated fixme comment
The `TraitPredicate` no longer has constness as we have desugared it to work with the type system through const generics instead.
Add missing PartialOrd trait implementation doc for array
Analogously to vectors and slices, this PR documents the lexicographic sorting of PartialOrd as rustdoc comment on the trait implementation of PartialOrd for arrays.
Associated issue: #122073.
Make the lowering of `thir::ExprKind::If` easier to follow
This targets a few code patterns that I found very confusing when I first tried to understand what this code is doing.
No functional changes. I recommend looking at the changes individually, with whitespace hidden.
Uplift some feeding out of `associated_type_for_impl_trait_in_impl` and into queries
This PR moves the `type_of` and `generics_of` query feeding out of `associated_type_for_impl_trait_in_impl`, since eagerly feeding results in query cycles due to a subtle interaction with `resolve_bound_vars`.
Fixes#122019
r? spastorino
Do not try to format removed files
If you removed a file, `x fmt` would confusingly print
```
formatting modified file path/to/file.rs
```
and pass it to the formatting logic. Filter out files with `D` (removed) status
loongarch: add frecipe and relax target feature
This PR adds `frecipe` and `relax` target features to LoongArch:
* frecipe - Support frecipe.{s/d} and frsqrte.{s/d} instructions..
* relax - Enable Linker relaxation.
