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use super::EvalCtxt;
use rustc_middle::traits::solve::{inspect, CandidateSource, QueryResult};
use std::marker::PhantomData;
pub(in crate::solve) struct ProbeCtxt<'me, 'a, 'tcx, F, T> {
ecx: &'me mut EvalCtxt<'a, 'tcx>,
probe_kind: F,
_result: PhantomData<T>,
}
impl<'tcx, F, T> ProbeCtxt<'_, '_, 'tcx, F, T>
where
F: FnOnce(&T) -> inspect::ProbeKind<'tcx>,
{
pub(in crate::solve) fn enter(self, f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> T) -> T {
let ProbeCtxt { ecx: outer_ecx, probe_kind, _result } = self;
let mut nested_ecx = EvalCtxt {
infcx: outer_ecx.infcx,
variables: outer_ecx.variables,
var_values: outer_ecx.var_values,
predefined_opaques_in_body: outer_ecx.predefined_opaques_in_body,
max_input_universe: outer_ecx.max_input_universe,
search_graph: outer_ecx.search_graph,
nested_goals: outer_ecx.nested_goals.clone(),
tainted: outer_ecx.tainted,
inspect: outer_ecx.inspect.new_probe(),
};
let r = nested_ecx.infcx.probe(|_| f(&mut nested_ecx));
if !outer_ecx.inspect.is_noop() {
let probe_kind = probe_kind(&r);
nested_ecx.inspect.probe_kind(probe_kind);
outer_ecx.inspect.finish_probe(nested_ecx.inspect);
}
r
}
}
impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
/// `probe_kind` is only called when proof tree building is enabled so it can be
/// as expensive as necessary to output the desired information.
pub(in crate::solve) fn probe<F, T>(&mut self, probe_kind: F) -> ProbeCtxt<'_, 'a, 'tcx, F, T>
where
F: FnOnce(&T) -> inspect::ProbeKind<'tcx>,
{
ProbeCtxt { ecx: self, probe_kind, _result: PhantomData }
}
pub(in crate::solve) fn probe_misc_candidate(
&mut self,
name: &'static str,
) -> ProbeCtxt<
'_,
'a,
'tcx,
impl FnOnce(&QueryResult<'tcx>) -> inspect::ProbeKind<'tcx>,
QueryResult<'tcx>,
> {
ProbeCtxt {
ecx: self,
probe_kind: move |result: &QueryResult<'tcx>| inspect::ProbeKind::MiscCandidate {
name,
result: *result,
},
_result: PhantomData,
}
}
pub(in crate::solve) fn probe_trait_candidate(
&mut self,
source: CandidateSource,
) -> ProbeCtxt<
'_,
'a,
'tcx,
impl FnOnce(&QueryResult<'tcx>) -> inspect::ProbeKind<'tcx>,
QueryResult<'tcx>,
> {
ProbeCtxt {
ecx: self,
probe_kind: move |result: &QueryResult<'tcx>| inspect::ProbeKind::TraitCandidate {
source,
result: *result,
},
_result: PhantomData,
}
}
}
|
