1 use rustc::infer::canonical::{Canonical, QueryResponse};
2 use rustc::traits::query::{normalize::NormalizationResult, CanonicalProjectionGoal, NoSolution};
3 use rustc::traits::{self, ObligationCause, SelectionContext, TraitEngineExt};
4 use rustc::ty::query::Providers;
5 use rustc::ty::{ParamEnvAnd, TyCtxt};
7 use rustc_span::DUMMY_SP;
8 use std::sync::atomic::Ordering;
10 crate fn provide(p: &mut Providers<'_>) {
11 *p = Providers { normalize_projection_ty, ..*p };
14 fn normalize_projection_ty<'tcx>(
16 goal: CanonicalProjectionGoal<'tcx>,
17 ) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, NormalizationResult<'tcx>>>, NoSolution> {
18 debug!("normalize_provider(goal={:#?})", goal);
20 tcx.sess.perf_stats.normalize_projection_ty.fetch_add(1, Ordering::Relaxed);
21 tcx.infer_ctxt().enter_canonical_trait_query(
23 |infcx, fulfill_cx, ParamEnvAnd { param_env, value: goal }| {
24 let selcx = &mut SelectionContext::new(infcx);
25 let cause = ObligationCause::misc(DUMMY_SP, hir::DUMMY_HIR_ID);
26 let mut obligations = vec![];
27 let answer = traits::normalize_projection_type(
35 fulfill_cx.register_predicate_obligations(infcx, obligations);
36 Ok(NormalizationResult { normalized_ty: answer })