bjoernager/rust
bjoernager/rust
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Structurally normalize in the new solver

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This commit is contained in:
Michael Goulet 2023-04-23 19:58:24 +00:00
parent eaf10dcb70
commit 4cfafb275e
6 changed files with 181 additions and 29 deletions
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2
compiler/rustc_trait_selection/src/traits/mod.rs
View file

@ -17,6 +17,7 @@ pub mod query;
mod select;
mod specialize;
mod structural_match;
mod structural_normalize;
mod util;
mod vtable;
pub mod wf;
@ -62,6 +63,7 @@ pub use self::specialize::{
pub use self::structural_match::{
search_for_adt_const_param_violation, search_for_structural_match_violation,
};
pub use self::structural_normalize::StructurallyNormalizeExt;
pub use self::util::elaborate;
pub use self::util::{expand_trait_aliases, TraitAliasExpander};
pub use self::util::{get_vtable_index_of_object_method, impl_item_is_final, upcast_choices};

55
compiler/rustc_trait_selection/src/traits/structural_normalize.rs Normal file
View file

@ -0,0 +1,55 @@
use rustc_infer::infer::at::At;
use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc_infer::traits::{FulfillmentError, TraitEngine};
use rustc_middle::ty::{self, Ty};
use crate::traits::{query::evaluate_obligation::InferCtxtExt, NormalizeExt, Obligation};
pub trait StructurallyNormalizeExt<'tcx> {
fn structurally_normalize(
&self,
ty: Ty<'tcx>,
fulfill_cx: &mut dyn TraitEngine<'tcx>,
) -> Result<Ty<'tcx>, Vec<FulfillmentError<'tcx>>>;
}
impl<'tcx> StructurallyNormalizeExt<'tcx> for At<'_, 'tcx> {
fn structurally_normalize(
&self,
mut ty: Ty<'tcx>,
fulfill_cx: &mut dyn TraitEngine<'tcx>,
) -> Result<Ty<'tcx>, Vec<FulfillmentError<'tcx>>> {
assert!(!ty.is_ty_var(), "should have resolved vars before calling");
if self.infcx.tcx.trait_solver_next() {
while let ty::Alias(ty::Projection, projection_ty) = *ty.kind() {
let new_infer_ty = self.infcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::NormalizeProjectionType,
span: self.cause.span,
});
let obligation = Obligation::new(
self.infcx.tcx,
self.cause.clone(),
self.param_env,
ty::Binder::dummy(ty::ProjectionPredicate {
projection_ty,
term: new_infer_ty.into(),
}),
);
if self.infcx.predicate_may_hold(&obligation) {
fulfill_cx.register_predicate_obligation(self.infcx, obligation);
let errors = fulfill_cx.select_where_possible(self.infcx);
if !errors.is_empty() {
return Err(errors);
}
ty = self.infcx.resolve_vars_if_possible(new_infer_ty);
} else {
break;
}
}
Ok(ty)
} else {
Ok(self.normalize(ty).into_value_registering_obligations(self.infcx, fulfill_cx))
}
}
}