bjoernager/rust
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Account for indirect cyclic requirements

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This commit is contained in:
Esteban Küber 2020-11-18 08:33:27 -08:00
parent 2098ade771
commit 352796402f
4 changed files with 102 additions and 2 deletions
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2
compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
View file

@ -200,6 +200,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
&obligation.predicate,
&obligation.cause.code,
&mut vec![],
&mut Default::default(),
);
err.emit();
@ -1700,6 +1701,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
&obligation.predicate,
&obligation.cause.code,
&mut vec![],
&mut Default::default(),
);
self.suggest_unsized_bound_if_applicable(err, obligation);
}

12
compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
View file

@ -7,6 +7,7 @@ use crate::autoderef::Autoderef;
use crate::infer::InferCtxt;
use crate::traits::normalize_projection_type;
use rustc_data_structures::fx::FxHashSet;
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_errors::{error_code, struct_span_err, Applicability, DiagnosticBuilder, Style};
use rustc_hir as hir;
@ -158,6 +159,7 @@ pub trait InferCtxtExt<'tcx> {
predicate: &T,
cause_code: &ObligationCauseCode<'tcx>,
obligated_types: &mut Vec<&ty::TyS<'tcx>>,
seen_requirements: &mut FxHashSet<DefId>,
) where
T: fmt::Display;
@ -1787,6 +1789,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
&obligation.predicate,
next_code.unwrap(),
&mut Vec::new(),
&mut Default::default(),
);
}
@ -1796,6 +1799,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
predicate: &T,
cause_code: &ObligationCauseCode<'tcx>,
obligated_types: &mut Vec<&ty::TyS<'tcx>>,
seen_requirements: &mut FxHashSet<DefId>,
) where
T: fmt::Display,
{
@ -2050,12 +2054,14 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
&parent_predicate,
&data.parent_code,
obligated_types,
seen_requirements,
)
});
}
}
ObligationCauseCode::ImplDerivedObligation(ref data) => {
let mut parent_trait_ref = self.resolve_vars_if_possible(data.parent_trait_ref);
let parent_def_id = parent_trait_ref.def_id();
err.note(&format!(
"required because of the requirements on the impl of `{}` for `{}`",
parent_trait_ref.print_only_trait_path(),
@ -2066,10 +2072,12 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
let mut data = data;
let mut redundant = false;
let mut count = 0;
seen_requirements.insert(parent_def_id);
while let ObligationCauseCode::ImplDerivedObligation(child) = &*data.parent_code {
// Skip redundant recursive obligation notes. See `ui/issue-20413.rs`.
let child_trait_ref = self.resolve_vars_if_possible(child.parent_trait_ref);
if parent_trait_ref.def_id() != child_trait_ref.def_id() {
let child_def_id = child_trait_ref.def_id();
if seen_requirements.insert(child_def_id) {
break;
}
count += 1;
@ -2093,6 +2101,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
&parent_predicate,
&data.parent_code,
obligated_types,
seen_requirements,
)
});
}
@ -2106,6 +2115,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
&parent_predicate,
&data.parent_code,
obligated_types,
seen_requirements,
)
});
}