Silence some follow-up errors [1/x]
this is one piece of the requested cleanups from https://github.com/rust-lang/rust/pull/117449
When we use `-> impl SomeTrait<_>` as a return type, we are both using the "infer return type suggestion" code path, and the infer opaque type code path within the same function. That can lead to confusing diagnostics, so silence all opaque type diagnostics in that case.
Cleanup things in and around `Diagnostic`
These changes all arose when I was looking closely at how to simplify `DiagCtxtInner::emit_diagnostic`.
r? `@compiler-errors`
Pass LLVM error message back to pass wrapper.
When rustc fails to load a plugin, it should provide more detailed error message. Before this PR, rustc prints:
```
error: failed to run LLVM passes: Failed to load pass pluginPLUGIN_NAME.so
```
This PR passes LLVM errors back to rustc. After this PR, rustc prints:
```
error: failed to run LLVM passes: Could not load library 'PLUGIN_NAME.so': PLUGIN_NAME.so: undefined symbol: _ZN4llvm9DebugFlagE
```
This PR only contains usability improvements and does not change any functionality. Thus, no new unit test is implemented.
Of the error levels satisfying `is_error`, `Level::Error` is the only
one that can be a lint, so there's no need to check for it.
(And even if it wasn't, it would make more sense to include
non-`Error`-but-`is_error` lints under `lint_err_count` than under
`err_count`.)
There are four functions that adjust error and warning counts:
- `stash_diagnostic` (increment)
- `steal_diagnostic` (decrement)
- `emit_stashed_diagnostics) (decrement)
- `emit_diagnostic` (increment)
The first three all behave similarly, and only update `warn_count` for
forced warnings. But the last one updates `warn_count` for both forced
and non-forced warnings.
Seems like a bug. How should it be fixed? Well, `warn_count` is only
used in one place: `DiagCtxtInner::drop`, where it's part of the
condition relating to the printing of `good_path_delayed_bugs`. The
intention of that condition seems to be "have any errors been printed?"
so this commit replaces `warn_count` with `has_printed`, which is set
when printing occurs. This is simpler than all the ahead-of-time
incrementing and decrementing.
`is_force_warn` is only possible for diagnostics with `Level::Warning`,
but it is currently stored in `Diagnostic::code`, which every diagnostic
has.
This commit:
- removes the boolean `DiagnosticId::Lint::is_force_warn` field;
- adds a `ForceWarning` variant to `Level`.
Benefits:
- The common `Level::Warning` case now has no arguments, replacing
lots of `Warning(None)` occurrences.
- `rustc_session::lint::Level` and `rustc_errors::Level` are more
similar, both having `ForceWarning` and `Warning`.
Diagnostic API fixes
Some improvements to diagnostic APIs: improve some naming, use shortcuts in more places, and add a couple of missing methods.
r? `@compiler-errors`
Avoid silencing relevant follow-up errors
r? `@matthewjasper`
This PR only adds new errors to tests that are already failing and fixes one ICE.
Several tests were changed to not emit new errors. I believe all of them were faulty tests, and not explicitly testing for the code that had new errors.
This lets us avoid the use of `DiagnosticBuilder::into_diagnostic` in
miri, when then means that `DiagnosticBuilder::into_diagnostic` can
become private, being now only used by `stash` and `buffer`.
In #119606 I added them and used a `_mv` suffix, but that wasn't great.
A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
`with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.
The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.
Thanks to @compiler-errors for the suggestion.
We have `span_delayed_bug` and often pass it a `DUMMY_SP`. This commit
adds `delayed_bug`, which matches pairs like `err`/`span_err` and
`warn`/`span_warn`.
- `struct_foo` + `emit` -> `foo`
- `create_foo` + `emit` -> `emit_foo`
I have made recent commits in other PRs that have removed some of these
shortcuts for combinations with few uses, e.g.
`struct_span_err_with_code`. But for the remaining combinations that
have high levels of use, we might as well use them wherever possible.
Because it takes an error code after the span. This avoids the confusing
overlap with the `DiagCtxt::struct_span_err` method, which doesn't take
an error code.
`~const` trait and projection bounds do not imply their non-const counterparts
This PR removes the hack where we install a non-const trait and projection bound for every `const_trait` and `~const` projection bound we have in the AST. It ends up messing up more things than it fixes, see words below.
Fixes#119718
cc `@fmease` `@fee1-dead` `@oli-obk`
r? fee1-dead or one of y'all i don't care
---
My understanding is that this hack was added to support the following code:
```rust
pub trait Owo<X = <Self as Uwu>::T> {}
#[const_trait]
pub trait Uwu: Owo {}
```
Which is concretely lifted from in the `FromResidual` and `Try` traits. Since within the param-env of `trait Uwu`, we only know that `Self: ~const Uwu` and not `Self: Uwu`, the projection `<Self as Uwu>::T` is not satsifyable.
This causes problems such as #119718, since instantiations of `FnDef` types coming from `const fn` really do **only** implement one of `FnOnce` or `const FnOnce`!
---
In the long-term, I believe that such code should really look something more like:
```rust
#[const_trait]
pub trait Owo<X = <Self as ~const Uwu>::T> {}
#[const_trait]
pub trait Uwu: Owo {}
```
... and that we should introduce some sort of `<T as ~const Foo>::Bar` bound syntax, since due to the fact that `~const` bounds can be present in item bounds, e.g.
```rust
#[const_trait] trait Foo { type Bar: ~const Destruct; }
```
It's easy to see that `<T as Foo>::Bar` and `<T as ~const Foo>::Bar` (or `<T as const Foo>::Bar`) can be distinct types with distinct item bounds!
**Admission**: I know I've said before that I don't like `~const` projection syntax, I do at this point believe they're necessary to fully express bounds and types in a maybe-const world.
GNU/Hurd: unconditionally use inline stack probes
LLVM 11 has been unsupported since 45591408b1, so this doesn't need to be conditional on the LLVM version.
cc `@sthibaul`
Remove `-Zdont-buffer-diagnostics`.
It was added in #54232. It seems like it was aimed at NLL development, which is well in the past. Also, it looks like `-Ztreat-err-as-bug` can be used to achieve the same effect. So it doesn't seem necessary.
r? ``@pnkfelix``
Merge dead bb pruning and unreachable bb deduplication.
Both routines share the same basic structure: iterate on all bbs to identify work, and then renumber bbs.
We can do both at once.
unify query canonicalization mode
Exclude from canonicalization only the static lifetimes that appear in the param env because of #118965 . Any other occurrence can be canonicalized safely AFAICT.
r? `@lcnr`
Support async recursive calls (as long as they have indirection)
Before #101692, we stored coroutine witness types directly inside of the coroutine. That means that a coroutine could not contain itself (as a witness field) without creating a cycle in the type representation of the coroutine, which we detected with the `OpaqueTypeExpander`, which is used to detect cycles when expanding opaque types after that are inferred to contain themselves.
After `-Zdrop-tracking-mir` was stabilized, we no longer store these generator witness fields directly, but instead behind a def-id based query. That means there is no technical obstacle in the compiler preventing coroutines from containing themselves per se, other than the fact that for a coroutine to have a non-infinite layout, it must contain itself wrapped in a layer of allocation indirection (like a `Box`).
This means that it should be valid for this code to work:
```
async fn async_fibonacci(i: u32) -> u32 {
if i == 0 || i == 1 {
i
} else {
Box::pin(async_fibonacci(i - 1)).await
+ Box::pin(async_fibonacci(i - 2)).await
}
}
```
Whereas previously, you'd need to coerce the future to `Pin<Box<dyn Future<Output = ...>>` before `await`ing it, to prevent the async's desugared coroutine from containing itself across as await point.
This PR does two things:
1. Only report an error if an opaque expansion cycle is detected *not* through coroutine witness fields.
* Instead, if we find an opaque cycle through coroutine witness fields, we compute the layout of the coroutine. If that results in a cycle error, we report it as a recursive async fn.
4. Reworks the way we report layout errors having to do with coroutines, to make up for the diagnostic regressions introduced by (1.). We actually do even better now, pointing out the call sites of the recursion!
Adding alignment to the cases to test for specific error messages.
Adding alignment to the list of cases to test for specific error message. Covers `>`, `^` and `<`.
Pinging people who chimed in last time ( https://github.com/rust-lang/rust/pull/106805 ): ``@estebank`` , ``@compiler-errors`` and ``@Nilstrieb``
Add -Zuse-sync-unwind
Currently Rust uses async unwind by default, but async unwind will bring non-negligible size overhead. it would be nice to allow users to choose this.
In addition, async unwind currently prevents LLVM from generate compact unwind for MachO, if one wishes to generate compact unwind for MachO, then also needs this flag.
