region_outlives_predicate no snapshot

Author: lcnr

compiler/rustc_error_codes/src/error_codes.rs

@@ -559,7 +559,7 @@ E0790: include_str!("./error_codes/E0790.md"),
 //  E0273, // on_unimplemented #1
 //  E0274, // on_unimplemented #2
 //  E0278, // requirement is not satisfied
-    E0279, // requirement is not satisfied
+//  E0279,
     E0280, // requirement is not satisfied
 //  E0285, // overflow evaluation builtin bounds
 //  E0296, // replaced with a generic attribute input check

compiler/rustc_infer/src/infer/mod.rs

@@ -1061,16 +1061,11 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         &self,
         cause: &traits::ObligationCause<'tcx>,
         predicate: ty::PolyRegionOutlivesPredicate<'tcx>,
-    ) -> UnitResult<'tcx> {
-        self.commit_if_ok(|_snapshot| {
-            let ty::OutlivesPredicate(r_a, r_b) =
-                self.replace_bound_vars_with_placeholders(predicate);
-            let origin = SubregionOrigin::from_obligation_cause(cause, || {
-                RelateRegionParamBound(cause.span)
-            });
-            self.sub_regions(origin, r_b, r_a); // `b : a` ==> `a <= b`
-            Ok(())
-        })
+    ) {
+        let ty::OutlivesPredicate(r_a, r_b) = self.replace_bound_vars_with_placeholders(predicate);
+        let origin =
+            SubregionOrigin::from_obligation_cause(cause, || RelateRegionParamBound(cause.span));
+        self.sub_regions(origin, r_b, r_a); // `b : a` ==> `a <= b`
     }
 
     /// Number of type variables created so far.

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -793,9 +793,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                 }
                 ty::PredicateKind::RegionOutlives(binder) => {
                     let binder = bound_predicate.rebind(binder);
-                    if select.infcx().region_outlives_predicate(&dummy_cause, binder).is_err() {
-                        return false;
-                    }
+                    select.infcx().region_outlives_predicate(&dummy_cause, binder)
                 }
                 ty::PredicateKind::TypeOutlives(binder) => {
                     let binder = bound_predicate.rebind(binder);

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -789,24 +789,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                         span_bug!(span, "coerce requirement gave wrong error: `{:?}`", predicate)
                     }
 
-                    ty::PredicateKind::RegionOutlives(predicate) => {
-                        let predicate = bound_predicate.rebind(predicate);
-                        let predicate = self.resolve_vars_if_possible(predicate);
-                        let err = self
-                            .region_outlives_predicate(&obligation.cause, predicate)
-                            .err()
-                            .unwrap();
-                        struct_span_err!(
-                            self.tcx.sess,
-                            span,
-                            E0279,
-                            "the requirement `{}` is not satisfied (`{}`)",
-                            predicate,
-                            err,
-                        )
-                    }
-
-                    ty::PredicateKind::Projection(..) | ty::PredicateKind::TypeOutlives(..) => {
+                    ty::PredicateKind::RegionOutlives(..)
+                    | ty::PredicateKind::Projection(..)
+                    | ty::PredicateKind::TypeOutlives(..) => {
                         let predicate = self.resolve_vars_if_possible(obligation.predicate);
                         struct_span_err!(
                             self.tcx.sess,

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -359,15 +359,10 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
 
                 ty::PredicateKind::RegionOutlives(data) => {
                     if infcx.considering_regions || data.has_placeholders() {
-                        match infcx
-                            .region_outlives_predicate(&obligation.cause, Binder::dummy(data))
-                        {
-                            Ok(()) => ProcessResult::Changed(vec![]),
-                            Err(_) => ProcessResult::Error(CodeSelectionError(Unimplemented)),
-                        }
-                    } else {
-                        ProcessResult::Changed(vec![])
+                        infcx.region_outlives_predicate(&obligation.cause, Binder::dummy(data));
                     }
+
+                    ProcessResult::Changed(vec![])
                 }
 
                 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(t_a, r_b)) => {

src/tools/tidy/src/error_codes_check.rs

@@ -10,8 +10,8 @@ use regex::Regex;
 
 // A few of those error codes can't be tested but all the others can and *should* be tested!
 const EXEMPTED_FROM_TEST: &[&str] = &[
-    "E0279", "E0313", "E0377", "E0461", "E0462", "E0465", "E0476", "E0490", "E0514", "E0519",
-    "E0523", "E0554", "E0640", "E0717", "E0729", "E0789",
+    "E0313", "E0377", "E0461", "E0462", "E0465", "E0476", "E0490", "E0514", "E0519", "E0523",
+    "E0554", "E0640", "E0717", "E0729", "E0789",
 ];
 
 // Some error codes don't have any tests apparently...