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Extract ImplSubject information

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Santiago Pastorino 2022-03-20 00:12:03 -03:00
parent 91b52148eb
commit 0cd03c917c
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GPG key ID: 8131A24E0C79EFAF
3 changed files with 50 additions and 37 deletions
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71
compiler/rustc_trait_selection/src/traits/coherence.rs
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@ -24,7 +24,7 @@ use rustc_middle::traits::specialization_graph::OverlapMode;
use rustc_middle::ty::fast_reject::{self, TreatParams};
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::subst::Subst;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_middle::ty::{self, ImplSubject, Ty, TyCtxt};
use rustc_span::symbol::sym;
use rustc_span::DUMMY_SP;
use std::fmt::Debug;
@ -307,46 +307,47 @@ fn negative_impl<'cx, 'tcx>(
// create a parameter environment corresponding to a (placeholder) instantiation of impl1
let impl1_env = tcx.param_env(impl1_def_id);
if let Some(impl1_trait_ref) = tcx.impl_trait_ref(impl1_def_id) {
// Normalize the trait reference. The WF rules ought to ensure
// that this always succeeds.
let impl1_trait_ref = match traits::fully_normalize(
&infcx,
FulfillmentContext::new(),
ObligationCause::dummy(),
impl1_env,
impl1_trait_ref,
) {
Ok(impl1_trait_ref) => impl1_trait_ref,
Err(err) => {
bug!("failed to fully normalize {:?}: {:?}", impl1_trait_ref, err);
}
};
match tcx.impl_header(impl1_def_id) {
ImplSubject::Trait(impl1_trait_ref) => {
// Normalize the trait reference. The WF rules ought to ensure
// that this always succeeds.
let impl1_trait_ref = match traits::fully_normalize(
&infcx,
FulfillmentContext::new(),
ObligationCause::dummy(),
impl1_env,
impl1_trait_ref,
) {
Ok(impl1_trait_ref) => impl1_trait_ref,
Err(err) => {
bug!("failed to fully normalize {:?}: {:?}", impl1_trait_ref, err);
}
};
// Attempt to prove that impl2 applies, given all of the above.
let selcx = &mut SelectionContext::new(&infcx);
let impl2_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl2_def_id);
let (impl2_trait_ref, obligations) =
impl_trait_ref_and_oblig(selcx, impl1_env, impl2_def_id, impl2_substs);
// Attempt to prove that impl2 applies, given all of the above.
let selcx = &mut SelectionContext::new(&infcx);
let impl2_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl2_def_id);
let (impl2_trait_ref, obligations) =
impl_trait_ref_and_oblig(selcx, impl1_env, impl2_def_id, impl2_substs);
!obligations_satisfiable(
&infcx,
impl1_env,
impl1_def_id,
impl1_trait_ref,
impl2_trait_ref,
obligations,
)
} else {
let ty1 = tcx.type_of(impl1_def_id);
let ty2 = tcx.type_of(impl2_def_id);
!obligations_satisfiable(&infcx, impl1_env, impl1_def_id, ty1, ty2, iter::empty())
!equate(
&infcx,
impl1_env,
impl1_def_id,
impl1_trait_ref,
impl2_trait_ref,
obligations,
)
}
ImplSubject::Inherent(ty1) => {
let ty2 = tcx.type_of(impl2_def_id);
!equate(&infcx, impl1_env, impl1_def_id, ty1, ty2, iter::empty())
}
}
})
}
fn obligations_satisfiable<'cx, 'tcx, T: Debug + ToTrace<'tcx>>(
fn equate<'cx, 'tcx, T: Debug + ToTrace<'tcx>>(
infcx: &InferCtxt<'cx, 'tcx>,
impl1_env: ty::ParamEnv<'tcx>,
impl1_def_id: DefId,