diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs index db7e4fe45ef7..d20cf556b71c 100644 --- a/src/librustc/ty/sty.rs +++ b/src/librustc/ty/sty.rs @@ -390,14 +390,21 @@ impl<'a, 'gcx, 'tcx> ClosureSubsts<'tcx> { state.map(move |d| d.ty.subst(tcx, self.substs)) } + /// This is the types of the fields of a generate which + /// is available before the generator transformation. + /// It includes the upvars and the state discriminant which is u32. + pub fn pre_transforms_tys(self, def_id: DefId, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> + impl Iterator> + 'a + { + self.upvar_tys(def_id, tcx).chain(iter::once(tcx.types.u32)) + } + /// This is the types of all the fields stored in a generator. /// It includes the upvars, state types and the state discriminant which is u32. pub fn field_tys(self, def_id: DefId, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> impl Iterator> + 'a { - let upvars = self.upvar_tys(def_id, tcx); - let state = self.state_tys(def_id, tcx); - upvars.chain(iter::once(tcx.types.u32)).chain(state) + self.pre_transforms_tys(def_id, tcx).chain(self.state_tys(def_id, tcx)) } } diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs index 9dcd4435580a..dc302b6cc354 100644 --- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs +++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs @@ -533,15 +533,17 @@ impl<'a, 'b, 'gcx, 'tcx> TypeVerifier<'a, 'b, 'gcx, 'tcx> { } } ty::TyGenerator(def_id, substs, _) => { - // Try upvars first. `field_tys` requires final optimized MIR. - if let Some(ty) = substs.upvar_tys(def_id, tcx).nth(field.index()) { + // Try pre-transform fields first (upvars and current state) + if let Some(ty) = substs.pre_transforms_tys(def_id, tcx).nth(field.index()) { return Ok(ty); } + // Then try `field_tys` which contains all the fields, but it + // requires the final optimized MIR. return match substs.field_tys(def_id, tcx).nth(field.index()) { Some(ty) => Ok(ty), None => Err(FieldAccessError::OutOfRange { - field_count: substs.field_tys(def_id, tcx).count() + 1, + field_count: substs.field_tys(def_id, tcx).count(), }), }; } @@ -1233,13 +1235,16 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> { } } AggregateKind::Generator(def_id, substs, _) => { - if let Some(ty) = substs.upvar_tys(def_id, tcx).nth(field_index) { + // Try pre-transform fields first (upvars and current state) + if let Some(ty) = substs.pre_transforms_tys(def_id, tcx).nth(field_index) { Ok(ty) } else { + // Then try `field_tys` which contains all the fields, but it + // requires the final optimized MIR. match substs.field_tys(def_id, tcx).nth(field_index) { Some(ty) => Ok(ty), None => Err(FieldAccessError::OutOfRange { - field_count: substs.field_tys(def_id, tcx).count() + 1, + field_count: substs.field_tys(def_id, tcx).count(), }), } } diff --git a/src/test/ui/generator/generator-with-nll.stderr b/src/test/ui/generator/generator-with-nll.stderr index 0a52a928f69d..0f7d2e540d80 100644 --- a/src/test/ui/generator/generator-with-nll.stderr +++ b/src/test/ui/generator/generator-with-nll.stderr @@ -1,12 +1,3 @@ -error[E0626]: borrow may still be in use when generator yields (Mir) - --> $DIR/generator-with-nll.rs:20:17 - | -20 | let b = &mut true; //~ ERROR borrow may still be in use when generator yields (Ast) - | ^^^^^^^^^ -21 | //~^ borrow may still be in use when generator yields (Mir) -22 | yield (); - | -------- possible yield occurs here - error[E0626]: borrow may still be in use when generator yields (Ast) --> $DIR/generator-with-nll.rs:19:23 | @@ -25,5 +16,14 @@ error[E0626]: borrow may still be in use when generator yields (Ast) 22 | yield (); | -------- possible yield occurs here +error[E0626]: borrow may still be in use when generator yields (Mir) + --> $DIR/generator-with-nll.rs:20:17 + | +20 | let b = &mut true; //~ ERROR borrow may still be in use when generator yields (Ast) + | ^^^^^^^^^ +21 | //~^ borrow may still be in use when generator yields (Mir) +22 | yield (); + | -------- possible yield occurs here + error: aborting due to 3 previous errors diff --git a/src/test/ui/generator/yield-while-local-borrowed.stderr b/src/test/ui/generator/yield-while-local-borrowed.stderr index 7961dd974413..114fe8ffcab0 100644 --- a/src/test/ui/generator/yield-while-local-borrowed.stderr +++ b/src/test/ui/generator/yield-while-local-borrowed.stderr @@ -1,12 +1,3 @@ -error[E0626]: borrow may still be in use when generator yields (Mir) - --> $DIR/yield-while-local-borrowed.rs:24:17 - | -24 | let a = &mut 3; - | ^^^^^^ -... -27 | yield(); - | ------- possible yield occurs here - error[E0626]: borrow may still be in use when generator yields (Ast) --> $DIR/yield-while-local-borrowed.rs:24:22 | @@ -25,6 +16,15 @@ error[E0626]: borrow may still be in use when generator yields (Ast) 55 | yield(); | ------- possible yield occurs here +error[E0626]: borrow may still be in use when generator yields (Mir) + --> $DIR/yield-while-local-borrowed.rs:24:17 + | +24 | let a = &mut 3; + | ^^^^^^ +... +27 | yield(); + | ------- possible yield occurs here + error[E0626]: borrow may still be in use when generator yields (Mir) --> $DIR/yield-while-local-borrowed.rs:52:21 |