bjoernager/rust
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Fall back when relating two opaques by substs in MIR typeck

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This commit is contained in:
Michael Goulet 2022-08-03 03:16:31 +00:00
parent 34a6cae28e
commit 28b6373b1d
5 changed files with 95 additions and 24 deletions
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54
compiler/rustc_infer/src/infer/nll_relate/mod.rs
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@ -396,6 +396,32 @@ where
generalizer.relate(value, value)
}
fn relate_opaques(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) };
let mut generalize = |ty, ty_is_expected| {
let var = self.infcx.next_ty_var_id_in_universe(
TypeVariableOrigin {
kind: TypeVariableOriginKind::MiscVariable,
span: self.delegate.span(),
},
ty::UniverseIndex::ROOT,
);
if ty_is_expected {
self.relate_ty_var((ty, var))
} else {
self.relate_ty_var((var, ty))
}
};
let (a, b) = match (a.kind(), b.kind()) {
(&ty::Opaque(..), _) => (a, generalize(b, false)?),
(_, &ty::Opaque(..)) => (generalize(a, true)?, b),
_ => unreachable!(),
};
self.delegate.register_opaque_type(a, b, true)?;
trace!(a = ?a.kind(), b = ?b.kind(), "opaque type instantiated");
Ok(a)
}
}
/// When we instantiate an inference variable with a value in
@ -572,32 +598,12 @@ where
(&ty::Infer(ty::TyVar(vid)), _) => self.relate_ty_var((vid, b)),
(&ty::Opaque(a_def_id, _), &ty::Opaque(b_def_id, _)) if a_def_id == b_def_id => {
self.infcx.super_combine_tys(self, a, b)
infcx.commit_if_ok(|_| infcx.super_combine_tys(self, a, b)).or_else(|err| {
if a_def_id.is_local() { self.relate_opaques(a, b) } else { Err(err) }
})
}
(&ty::Opaque(did, ..), _) | (_, &ty::Opaque(did, ..)) if did.is_local() => {
let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) };
let mut generalize = |ty, ty_is_expected| {
let var = infcx.next_ty_var_id_in_universe(
TypeVariableOrigin {
kind: TypeVariableOriginKind::MiscVariable,
span: self.delegate.span(),
},
ty::UniverseIndex::ROOT,
);
if ty_is_expected {
self.relate_ty_var((ty, var))
} else {
self.relate_ty_var((var, ty))
}
};
let (a, b) = match (a.kind(), b.kind()) {
(&ty::Opaque(..), _) => (a, generalize(b, false)?),
(_, &ty::Opaque(..)) => (generalize(a, true)?, b),
_ => unreachable!(),
};
self.delegate.register_opaque_type(a, b, true)?;
trace!(a = ?a.kind(), b = ?b.kind(), "opaque type instantiated");
Ok(a)
self.relate_opaques(a, b)
}
(&ty::Projection(projection_ty), _)