E0669 refers to a constraint that cannot be coerced into a single LLVM
value, unfortunately right now this uses the Span for the entire inline
assembly statement, which is less than ideal.
This commit preserves the Span from HIR, which lets us emit the error
using the Span for the operand itself in MIR.
Signed-off-by: Levente Kurusa <lkurusa@acm.org>
At some point, I had thought to use this code to handle equality
comparisons for the `IfEq` verify bounds; at that point, we might not
have had an infcx to talk about. But we wound up doing "SCC
representatives" instead, so that's fine.
Instead, we talk about:
- creating the "next" universe
- universes "extending" one another
- and `u1.can_name(u2)`, meaning that `u1` contains all names from `u2`
[NLL] Check user types are well-formed
Also contains a change of span for AscribeUserType.
I'm not quite sure if this was what @nikomatsakis was thinking.
Closes#54620
r? @nikomatsakis
Better Diagnostic for Trait Object Capture
Part of #52663.
This commit enhances `LaterUseKind` detection to identify when a borrow
is captured by a trait object which helps explain why there is a borrow
error.
r? @nikomatsakis
cc @pnkfelix
Now when a `FnMut` closure is returning a closure that contains a
reference to a captured variable, we provide an error that makes it more
clear what is happening.
[NLL] Improve closure region bound errors
Previously, we would report free region errors that originate from closure with the span of the closure and a "closure body requires ..." message. This is now updated to use a reason and span from inside the closure.
This commit updates the captured trait object search logic to look for
unsized casts to boxed types rather than for functions that returned
trait objects.
Changed `BorrowExplanation::UsedLaterWhenDropped` to handle both named
locals and also unnamed (aka temporaries).
If the dropped temporary does not implement `Drop`, then we print its
full type; but when the dropped temporary is itself an ADT `D` that
implements `Drop`, then diagnostic points the user directly at `D`.
This is preparation for allowing the `BorrowExplanation` carry things
like `mir::Location` or `mir::Local` and still be able to generate
usable diagnostic text.
(I found it confusing to have calls to an `emit` method in our
error_reporting module where that `emit` method *wasn't* the
`DiagnosticBuffer::emit` method.)
