bjoernager/rust
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Tweak assoc type obligation spans

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* Point at RHS of associated type in obligation span
* Point at `impl` assoc type on projection error
* Reduce verbosity of recursive obligations
* Point at source of binding lifetime obligation
* Tweak "required bound" note
* Tweak "expected... found opaque (return) type" labels
* Point at set type in impl assoc type WF errors
This commit is contained in:
Esteban Kuber 2021-12-11 02:20:41 +00:00
parent f0448f44bc
commit 5e1972eba7
92 changed files with 503 additions and 257 deletions
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39
compiler/rustc_infer/src/infer/error_reporting/mod.rs
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@ -1429,6 +1429,15 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
}
}
/// Extend a type error with extra labels pointing at "non-trivial" types, like closures and
/// the return type of `async fn`s.
///
/// `secondary_span` gives the caller the opportunity to expand `diag` with a `span_label`.
///
/// `swap_secondary_and_primary` is used to make projection errors in particular nicer by using
/// the message in `secondary_span` as the primary label, and apply the message that would
/// otherwise be used for the primary label on the `secondary_span` `Span`. This applies on
/// E0271, like `src/test/ui/issues/issue-39970.stderr`.
pub fn note_type_err(
&self,
diag: &mut DiagnosticBuilder<'tcx>,
@ -1436,6 +1445,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
secondary_span: Option<(Span, String)>,
mut values: Option<ValuePairs<'tcx>>,
terr: &TypeError<'tcx>,
swap_secondary_and_primary: bool,
) {
let span = cause.span(self.tcx);
debug!("note_type_err cause={:?} values={:?}, terr={:?}", cause, values, terr);
@ -1612,9 +1622,32 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
match terr {
TypeError::ObjectUnsafeCoercion(_) => {}
_ => {
diag.span_label(span, terr.to_string());
let mut label_or_note = |span: Span, msg: &str| {
if &[span] == diag.span.primary_spans() {
diag.span_label(span, msg);
} else {
diag.span_note(span, msg);
}
};
if let Some((sp, msg)) = secondary_span {
diag.span_label(sp, msg);
if swap_secondary_and_primary {
let terr = if let Some(infer::ValuePairs::Types(infer::ExpectedFound {
expected,
..
})) = values
{
format!("expected this to be `{}`", expected)
} else {
terr.to_string()
};
label_or_note(sp, &terr);
label_or_note(span, &msg);
} else {
label_or_note(span, &terr.to_string());
label_or_note(sp, &msg);
}
} else {
label_or_note(span, &terr.to_string());
}
}
};
@ -2048,7 +2081,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
struct_span_err!(self.tcx.sess, span, E0644, "{}", failure_str)
}
};
self.note_type_err(&mut diag, &trace.cause, None, Some(trace.values), terr);
self.note_type_err(&mut diag, &trace.cause, None, Some(trace.values), terr, false);
diag
}