improve comments for `simplify_type`
Should now correctly describe what's going on. Experimented with checking the invariant for projections
but that ended up requiring fairly involved changes. I assume that it is not possible to get unsoundness here,
at least for now and I can pretty much guarantee that it's impossible to trigger it by accident.
r? `````@nikomatsakis````` cc #92721
Check method input expressions once
If the user mistakenly forgets to wrap their method args in a tuple, then the compiler tries to check that types within the tuple match the expression args. This means we call `check_expr` once within this diagnostic code, so when we check the expr once again in `demand_compatible`, we attempt to apply expr adjustments twice, leading to ICEs.
This PR attempts to fix this by skipping the expression type check in `demand_compatible` if we have detected an method arg mismatch at all.
This does lead to a single UI test regressing slightly, due to a diagnostic disappearing, though I don't know if it is generally meaningful to even raise an type error after noting that the argument count is incorrect in a function call, since the user might be providing (in-context) meaningless expressions to the wrong method.
I can adjust this to be a bit more targeted (to just skip checking exprs in `demand_compatible` in the tuple case) if this UI test regression is a problem.
fixes#94334
cc #94291
Also drive-by fixup of `.node_type(expr.hir_id)` to `.expr_ty(expr)`, since that method exists.
Generalize "remove `&`" and "add `*`" suggestions to more than one deref
Suggest removing more than one `&` and `&mut`, along with suggesting adding more than one `*` (or a combination of the two).
r? `@estebank`
(since you're experienced with these types of suggestions, feel free to reassign)
Fix ICE when passing block to while-loop condition
We were incorrectly delaying a bug when we passed _any_ block (that evaluated to `()`) to a while loop. This PR makes the check a bit more sophisticated.
We should only suppress the error here in cases that are equivalent to those we find in #93574 (i.e. only while loop conditions that have destructuring assignment expressions in them).
Fixes#93997
cc `@estebank` who added this code
I would not be opposed to removing the delay-bug altogether, and just emitting this error always. I much prefer duplicate errors over no errors.
fix a message
implement a rustfix-applicable suggestion
implement `suggest_floating_point_literal`
add `ObligationCauseCode::BinOp`
remove duplicate code
fix function names in uitests
use `Diagnostic` instead of `DiagnosticBuilder`
Rollup of 4 pull requests
Successful merges:
- #93850 (Don't ICE when an extern static is too big for the current architecture)
- #94154 (Wire up unstable rustc --check-cfg to rustdoc)
- #94353 (Fix debug_assert in unused lint pass)
- #94366 (Add missing item to release notes)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Don't ICE when an extern static is too big for the current architecture
Fixes#93760
Emit an error instead of ICEing when an `extern` static's size overflows the allowed maximum for the target.
Changes the error message in the existing `delay_span_bug` call to the true layout error, first for debugging purposes, but opted to leave in to potentially assist future developers as it was being reached in unexpected ways already.
Remove in band lifetimes
As discussed in t-lang backlog bonanza, the `in_band_lifetimes` FCP closed in favor for the feature not being stabilized. This PR removes `#![feature(in_band_lifetimes)]` in its entirety.
Let me know if this PR is too hasty, and if we should instead do something intermediate for deprecate the feature first.
r? `@scottmcm` (or feel free to reassign, just saw your last comment on #44524)
Closes#44524
Consider mutations as borrows in generator drop tracking
This is needed to match MIR more conservative approximation of any borrowed value being live across a suspend point (See #94067). This change considers an expression such as `x.y = z` to be a borrow of `x` and therefore keeps `x` live across suspend points.
r? `@nikomatsakis`
rustc_errors: let `DiagnosticBuilder::emit` return a "guarantee of emission".
That is, `DiagnosticBuilder` is now generic over the return type of `.emit()`, so we'll now have:
* `DiagnosticBuilder<ErrorReported>` for error (incl. fatal/bug) diagnostics
* can only be created via a `const L: Level`-generic constructor, that limits allowed variants via a `where` clause, so not even `rustc_errors` can accidentally bypass this limitation
* asserts `diagnostic.is_error()` on emission, just in case the construction restriction was bypassed (e.g. by replacing the whole `Diagnostic` inside `DiagnosticBuilder`)
* `.emit()` returns `ErrorReported`, as a "proof" token that `.emit()` was called
(though note that this isn't a real guarantee until after completing the work on
#69426)
* `DiagnosticBuilder<()>` for everything else (warnings, notes, etc.)
* can also be obtained from other `DiagnosticBuilder`s by calling `.forget_guarantee()`
This PR is a companion to other ongoing work, namely:
* #69426
and it's ongoing implementation:
#93222
the API changes in this PR are needed to get statically-checked "only errors produce `ErrorReported` from `.emit()`", but doesn't itself provide any really strong guarantees without those other `ErrorReported` changes
* #93244
would make the choices of API changes (esp. naming) in this PR fit better overall
In order to be able to let `.emit()` return anything trustable, several changes had to be made:
* `Diagnostic`'s `level` field is now private to `rustc_errors`, to disallow arbitrary "downgrade"s from "some kind of error" to "warning" (or anything else that doesn't cause compilation to fail)
* it's still possible to replace the whole `Diagnostic` inside the `DiagnosticBuilder`, sadly, that's harder to fix, but it's unlikely enough that we can paper over it with asserts on `.emit()`
* `.cancel()` now consumes `DiagnosticBuilder`, preventing `.emit()` calls on a cancelled diagnostic
* it's also now done internally, through `DiagnosticBuilder`-private state, instead of having a `Level::Cancelled` variant that can be read (or worse, written) by the user
* this removes a hazard of calling `.cancel()` on an error then continuing to attach details to it, and even expect to be able to `.emit()` it
* warnings were switched to *only* `can_emit_warnings` on emission (instead of pre-cancelling early)
* `struct_dummy` was removed (as it relied on a pre-`Cancelled` `Diagnostic`)
* since `.emit()` doesn't consume the `DiagnosticBuilder` <sub>(I tried and gave up, it's much more work than this PR)</sub>,
we have to make `.emit()` idempotent wrt the guarantees it returns
* thankfully, `err.emit(); err.emit();` can return `ErrorReported` both times, as the second `.emit()` call has no side-effects *only* because the first one did do the appropriate emission
* `&mut Diagnostic` is now used in a lot of function signatures, which used to take `&mut DiagnosticBuilder` (in the interest of not having to make those functions generic)
* the APIs were already mostly identical, allowing for low-effort porting to this new setup
* only some of the suggestion methods needed some rework, to have the extra `DiagnosticBuilder` functionality on the `Diagnostic` methods themselves (that change is also present in #93259)
* `.emit()`/`.cancel()` aren't available, but IMO calling them from an "error decorator/annotator" function isn't a good practice, and can lead to strange behavior (from the caller's perspective)
* `.downgrade_to_delayed_bug()` was added, letting you convert any `.is_error()` diagnostic into a `delay_span_bug` one (which works because in both cases the guarantees available are the same)
This PR should ideally be reviewed commit-by-commit, since there is a lot of fallout in each.
r? `@estebank` cc `@Manishearth` `@nikomatsakis` `@mark-i-m`
better ObligationCause for normalization errors in `can_type_implement_copy`
Some logic is needed so we can point to the field when given totally nonsense types like `struct Foo(<u32 as Iterator>::Item);`
Fixes#93687
Do not suggest wrapping an item if it has ambiguous un-imported methods
If the method is defined for the receiver we have, but is ambiguous during probe, then it probably comes from one of several traits that just weren't `use`d. Don't suggest wrapping the receiver in `Box`/etc., even if that makes the method probe unambiguous.
Fixes#94218
Fix several asm! related issues
This is a combination of several fixes, each split into a separate commit. Splitting these into PRs is not practical since they conflict with each other.
Fixes#92378Fixes#85247
r? ``@nagisa``
Move ty::print methods to Drop-based scope guards
Primary goal is reducing codegen of the TLS access for each closure, which shaves ~3 seconds of bootstrap time over rustc as a whole.
