/// returns a span and `ArgKind` information that describes the
/// arguments it expects. This can be supplied to
/// `report_arg_count_mismatch`.
- fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Vec<ArgKind>)>;
+ fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span,
Option<Span>, Vec<ArgKind>)>;
/// Reports an error when the number of arguments needed by a
/// trait match doesn't match the number that the expression
expected_args: Vec<ArgKind>,
found_args: Vec<ArgKind>,
is_closure: bool,
+ closure_pipe_span: Option<Span>,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>;
/// Checks if the type implements one of `Fn`, `FnMut`, or `FnOnce`
}
pub trait TypeErrCtxtExt<'tcx> {
+ fn report_overflow_error<T>(
+ &self,
+ predicate: &T,
+ span: Span,
+ suggest_increasing_limit: bool,
+ mutate: impl FnOnce(&mut Diagnostic),
+ ) -> !
+ where
+ T: fmt::Display
+ + TypeFoldable<'tcx>
+ + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
+ <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
+
fn report_fulfillment_errors(
&self,
errors: &[FulfillmentError<'tcx>],
body_id: Option<hir::BodyId>,
) -> ErrorGuaranteed;
- fn report_overflow_error<T>(
+ fn report_overflow_obligation<T>(
&self,
obligation: &Obligation<'tcx, T>,
suggest_increasing_limit: bool,
) -> !
where
- T: fmt::Display
- + TypeFoldable<'tcx>
- + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
- <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
+ T: ToPredicate<'tcx> + Clone;
fn suggest_new_overflow_limit(&self, err: &mut Diagnostic);
- fn report_overflow_error_cycle(&self, cycle: &[PredicateObligation<'tcx>]) -> !;
+ fn report_overflow_obligation_cycle(&self, cycle: &[PredicateObligation<'tcx>]) -> !;
/// The `root_obligation` parameter should be the `root_obligation` field
/// from a `FulfillmentError`. If no `FulfillmentError` is available,
/// returns a span and `ArgKind` information that describes the
/// arguments it expects. This can be supplied to
/// `report_arg_count_mismatch`.
- fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Vec<ArgKind>)> {
+ fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span,
Option<Span>, Vec<ArgKind>)> {
let sm = self.tcx.sess.source_map();
let hir = self.tcx.hir();
Some(match node {
Node::Expr(&hir::Expr {
- kind: hir::ExprKind::Closure(&hir::Closure { body, fn_decl_span, .. }),
+ kind: hir::ExprKind::Closure(&hir::Closure { body, fn_decl_span, fn_arg_span, .. }),
..
}) => (
fn_decl_span,
+ fn_arg_span,
hir.body(body)
.params
.iter()
kind: hir::TraitItemKind::Fn(ref sig, _), ..
}) => (
sig.span,
+ None,
sig.decl
.inputs
.iter()
),
Node::Ctor(ref variant_data) => {
let span = variant_data.ctor_hir_id().map_or(DUMMY_SP, |id| hir.span(id));
- (span, vec![ArgKind::empty(); variant_data.fields().len()])
+ (span, None, vec![ArgKind::empty(); variant_data.fields().len()])
}
_ => panic!("non-FnLike node found: {:?}", node),
})
expected_args: Vec<ArgKind>,
found_args: Vec<ArgKind>,
is_closure: bool,
+ closure_arg_span: Option<Span>,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
let kind = if is_closure { "closure" } else { "function" };
if let Some(found_span) = found_span {
err.span_label(found_span, format!("takes {}", found_str));
- // move |_| { ... }
- // ^^^^^^^^-- def_span
- //
- // move |_| { ... }
- // ^^^^^-- prefix
- let prefix_span = self.tcx.sess.source_map().span_until_non_whitespace(found_span);
- // move |_| { ... }
- // ^^^-- pipe_span
- let pipe_span =
- if let Some(span) = found_span.trim_start(prefix_span) { span } else { found_span };
-
// Suggest to take and ignore the arguments with expected_args_length `_`s if
// found arguments is empty (assume the user just wants to ignore args in this case).
// For example, if `expected_args_length` is 2, suggest `|_, _|`.
if found_args.is_empty() && is_closure {
let underscores = vec!["_"; expected_args.len()].join(", ");
err.span_suggestion_verbose(
- pipe_span,
+ closure_arg_span.unwrap_or(found_span),
&format!(
"consider changing the closure to take and ignore the expected argument{}",
pluralize!(expected_args.len())
/// occurrences in any case.
fn report_overflow_error<T>(
&self,
- obligation: &Obligation<'tcx, T>,
+ predicate: &T,
+ span: Span,
suggest_increasing_limit: bool,
+ mutate: impl FnOnce(&mut Diagnostic),
) -> !
where
T: fmt::Display
+ Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
<T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
{
- let predicate = self.resolve_vars_if_possible(obligation.predicate.clone());
+ let predicate = self.resolve_vars_if_possible(predicate.clone());
let mut pred_str = predicate.to_string();
+
if pred_str.len() > 50 {
// We don't need to save the type to a file, we will be talking about this type already
// in a separate note when we explain the obligation, so it will be available that way.
}
let mut err = struct_span_err!(
self.tcx.sess,
- obligation.cause.span,
+ span,
E0275,
"overflow evaluating the requirement `{}`",
pred_str,
self.suggest_new_overflow_limit(&mut err);
}
- self.note_obligation_cause_code(
- &mut err,
- &obligation.predicate,
- obligation.param_env,
- obligation.cause.code(),
- &mut vec![],
- &mut Default::default(),
- );
+ mutate(&mut err);
err.emit();
self.tcx.sess.abort_if_errors();
bug!();
}
+ /// Reports that an overflow has occurred and halts compilation. We
+ /// halt compilation unconditionally because it is important that
+ /// overflows never be masked -- they basically represent computations
+ /// whose result could not be truly determined and thus we can't say
+ /// if the program type checks or not -- and they are unusual
+ /// occurrences in any case.
+ fn report_overflow_obligation<T>(
+ &self,
+ obligation: &Obligation<'tcx, T>,
+ suggest_increasing_limit: bool,
+ ) -> !
+ where
+ T: ToPredicate<'tcx> + Clone,
+ {
+ let predicate = obligation.predicate.clone().to_predicate(self.tcx);
+ let predicate = self.resolve_vars_if_possible(predicate);
+ self.report_overflow_error(
+ &predicate,
+ obligation.cause.span,
+ suggest_increasing_limit,
+ |err| {
+ self.note_obligation_cause_code(
+ err,
+ &predicate,
+ obligation.param_env,
+ obligation.cause.code(),
+ &mut vec![],
+ &mut Default::default(),
+ );
+ },
+ );
+ }
+
fn suggest_new_overflow_limit(&self, err: &mut Diagnostic) {
let suggested_limit = match self.tcx.recursion_limit() {
Limit(0) => Limit(2),
}
/// Reports that a cycle was detected which led to overflow and halts
- /// compilation. This is equivalent to `report_overflow_error` except
+ /// compilation. This is equivalent to `report_overflow_obligation` except
/// that we can give a more helpful error message (and, in particular,
/// we do not suggest increasing the overflow limit, which is not
/// going to help).
- fn report_overflow_error_cycle(&self, cycle: &[PredicateObligation<'tcx>]) -> ! {
+ fn report_overflow_obligation_cycle(&self, cycle: &[PredicateObligation<'tcx>]) -> ! {
let cycle = self.resolve_vars_if_possible(cycle.to_owned());
assert!(!cycle.is_empty());
// The 'deepest' obligation is most likely to have a useful
// cause 'backtrace'
- self.report_overflow_error(cycle.iter().max_by_key(|p| p.recursion_depth).unwrap(), false);
+ self.report_overflow_obligation(
+ cycle.iter().max_by_key(|p| p.recursion_depth).unwrap(),
+ false,
+ );
}
fn report_selection_error(
// can get a better error message by performing HIR-based well-formedness checking.
if let ObligationCauseCode::WellFormed(Some(wf_loc)) =
root_obligation.cause.code().peel_derives()
+ && !obligation.predicate.has_non_region_infer()
{
if let Some(cause) = self
.tcx
obligation.cause.code(),
)
} else {
- let (closure_span, found) = found_did
+ let (closure_span, closure_arg_span, found) = found_did
.and_then(|did| {
let node = self.tcx.hir().get_if_local(did)?;
- let (found_span, found) = self.get_fn_like_arguments(node)?;
- Some((Some(found_span), found))
+ let (found_span, closure_arg_span, found) =
+ self.get_fn_like_arguments(node)?;
+ Some((Some(found_span), closure_arg_span, found))
})
- .unwrap_or((found_span, found));
+ .unwrap_or((found_span, None, found));
self.report_arg_count_mismatch(
span,
expected,
found,
found_trait_ty.is_closure(),
+ closure_arg_span,
)
}
}
diag.emit();
}
FulfillmentErrorCode::CodeCycle(ref cycle) => {
- self.report_overflow_error_cycle(cycle);
+ self.report_overflow_obligation_cycle(cycle);
}
}
}
}
self.probe(|_| {
- let mut err = error.err;
- let mut values = None;
+ let ocx = ObligationCtxt::new_in_snapshot(self);
// try to find the mismatched types to report the error with.
//
// this can fail if the problem was higher-ranked, in which
// cause I have no idea for a good error message.
let bound_predicate = predicate.kind();
- if let ty::PredicateKind::Clause(ty::Clause::Projection(data)) =
+ let (values, err) = if let ty::PredicateKind::Clause(ty::Clause::Projection(data)) =
bound_predicate.skip_binder()
{
- let mut selcx = SelectionContext::new(self);
let data = self.replace_bound_vars_with_fresh_vars(
obligation.cause.span,
infer::LateBoundRegionConversionTime::HigherRankedType,
bound_predicate.rebind(data),
);
- let mut obligations = vec![];
- // FIXME(normalization): Change this to use `At::normalize`
- let normalized_ty = super::normalize_projection_type(
- &mut selcx,
+ let normalized_ty = ocx.normalize(
+ &obligation.cause,
obligation.param_env,
- data.projection_ty,
- obligation.cause.clone(),
- 0,
- &mut obligations,
+ self.tcx
+ .mk_projection(data.projection_ty.item_def_id, data.projection_ty.substs),
);
debug!(?obligation.cause, ?obligation.param_env);
| ObligationCauseCode::ObjectCastObligation(..)
| ObligationCauseCode::OpaqueType
);
- if let Err(new_err) = self.at(&obligation.cause, obligation.param_env).eq_exp(
+ let expected_ty = data.term.ty().unwrap_or_else(|| self.tcx.ty_error());
+
+ // constrain inference variables a bit more to nested obligations from normalize so
+ // we can have more helpful errors.
+ ocx.select_where_possible();
+
+ if let Err(new_err) = ocx.eq_exp(
+ &obligation.cause,
+ obligation.param_env,
is_normalized_ty_expected,
normalized_ty,
- data.term,
+ expected_ty,
) {
- values = Some((data, is_normalized_ty_expected, normalized_ty, data.term));
- err = new_err;
+ (Some((data, is_normalized_ty_expected, normalized_ty, expected_ty)), new_err)
+ } else {
+ (None, error.err)
}
- }
+ } else {
+ (None, error.err)
+ };
let msg = values
.and_then(|(predicate, _, normalized_ty, expected_ty)| {
- self.maybe_detailed_projection_msg(predicate, normalized_ty, expected_ty)
+ self.maybe_detailed_projection_msg(
+ predicate,
+ normalized_ty.into(),
+ expected_ty.into(),
+ )
})
.unwrap_or_else(|| format!("type mismatch resolving `{}`", predicate));
let mut diag = struct_span_err!(self.tcx.sess, obligation.cause.span, E0271, "{msg}");
&mut diag,
&obligation.cause,
secondary_span,
- values.map(|(_, is_normalized_ty_expected, normalized_ty, term)| {
+ values.map(|(_, is_normalized_ty_expected, normalized_ty, expected_ty)| {
infer::ValuePairs::Terms(ExpectedFound::new(
is_normalized_ty_expected,
- normalized_ty,
- term,
+ normalized_ty.into(),
+ expected_ty.into(),
))
}),
err,
&self,
trait_pred: ty::PolyTraitPredicate<'tcx>,
) -> Vec<ImplCandidate<'tcx>> {
- self.tcx
+ let mut candidates: Vec<_> = self
+ .tcx
.all_impls(trait_pred.def_id())
.filter_map(|def_id| {
if self.tcx.impl_polarity(def_id) == ty::ImplPolarity::Negative
self.fuzzy_match_tys(trait_pred.skip_binder().self_ty(), imp.self_ty(), false)
.map(|similarity| ImplCandidate { trait_ref: imp, similarity })
})
- .collect()
+ .collect();
+ if candidates.iter().any(|c| matches!(c.similarity, CandidateSimilarity::Exact { .. })) {
+ // If any of the candidates is a perfect match, we don't want to show all of them.
+ // This is particularly relevant for the case of numeric types (as they all have the
+ // same cathegory).
+ candidates.retain(|c| matches!(c.similarity, CandidateSimilarity::Exact { .. }));
+ }
+ candidates
}
fn report_similar_impl_candidates(
projects / rust.git / blobdiff