diff options
| -rw-r--r-- | src/librustc_mir/build/matches/mod.rs | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/src/librustc_mir/build/matches/mod.rs b/src/librustc_mir/build/matches/mod.rs index 552066e6797..7555827ff01 100644 --- a/src/librustc_mir/build/matches/mod.rs +++ b/src/librustc_mir/build/matches/mod.rs @@ -30,16 +30,6 @@ mod simplify; mod test; mod util; -/// Injects a borrow of `place`. The region is unknown at this point; we rely on NLL -/// inference to find an appropriate one. Therefore you can only call this when NLL -/// is turned on. -fn inject_borrow<'a, 'gcx, 'tcx>(tcx: ty::TyCtxt<'a, 'gcx, 'tcx>, - place: Place<'tcx>) - -> Rvalue<'tcx> { - assert!(tcx.use_mir_borrowck()); - Rvalue::Ref(tcx.types.re_empty, BorrowKind::Shared, place) -} - /// ArmHasGuard is isomorphic to a boolean flag. It indicates whether /// a match arm has a guard expression attached to it. #[derive(Copy, Clone, Debug)] @@ -67,8 +57,10 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> { // of `discriminant_place`, specifically by applying `Rvalue::Discriminant` // (which will work regardless of type) and storing the result in a temp. // - // FIXME: would just the borrow into `borrowed_input_temp` - // also achieve the desired effect here? TBD. + // NOTE: Under NLL, the above issue should no longer occur because it + // injects a borrow of the matched input, which should have the same effect + // as eddyb's hack. Once NLL is the default, we can remove the hack. + let dummy_source_info = self.source_info(span); let dummy_access = Rvalue::Discriminant(discriminant_place.clone()); let dummy_ty = dummy_access.ty(&self.local_decls, tcx); @@ -77,7 +69,12 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> { let source_info = self.source_info(span); let borrowed_input_temp = if tcx.generate_borrow_of_any_match_input() { - let borrowed_input = inject_borrow(tcx, discriminant_place.clone()); + // The region is unknown at this point; we rely on NLL + // inference to find an appropriate one. Therefore you can + // only use this when NLL is turned on. + assert!(tcx.use_mir_borrowck()); + let borrowed_input = + Rvalue::Ref(tcx.types.re_empty, BorrowKind::Shared, discriminant_place.clone()); let borrowed_input_ty = borrowed_input.ty(&self.local_decls, tcx); let borrowed_input_temp = self.temp(borrowed_input_ty, span); self.cfg.push_assign(block, source_info, &borrowed_input_temp, borrowed_input); |