diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc/ty/sty.rs | 24 | ||||
| -rw-r--r-- | src/librustc_mir/build/expr/as_rvalue.rs | 5 | ||||
| -rw-r--r-- | src/librustc_mir/transform/generator.rs | 13 |
3 files changed, 25 insertions, 17 deletions
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs index 9a90ccda914..1ac18f6117f 100644 --- a/src/librustc/ty/sty.rs +++ b/src/librustc/ty/sty.rs @@ -298,14 +298,10 @@ static_assert!(MEM_SIZE_OF_TY_KIND: ::std::mem::size_of::<TyKind<'_>>() == 24); /// /// ## Generators /// -/// Perhaps surprisingly, `ClosureSubsts` are also used for -/// generators. In that case, what is written above is only half-true -/// -- the set of type parameters is similar, but the role of CK and -/// CS are different. CK represents the "yield type" and CS -/// represents the "return type" of the generator. -/// -/// It'd be nice to split this struct into ClosureSubsts and -/// GeneratorSubsts, I believe. -nmatsakis +/// Generators are handled similarly in `GeneratorSubsts`. The set of +/// type parameters is similar, but the role of CK and CS are +/// different. CK represents the "yield type" and CS represents the +/// "return type" of the generator. #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable, HashStable)] pub struct ClosureSubsts<'tcx> { @@ -391,6 +387,7 @@ impl<'tcx> ClosureSubsts<'tcx> { } } +/// Similar to `ClosureSubsts`; see the above documentation for more. #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable, HashStable)] pub struct GeneratorSubsts<'tcx> { @@ -470,6 +467,11 @@ impl<'tcx> GeneratorSubsts<'tcx> { } impl<'a, 'gcx, 'tcx> GeneratorSubsts<'tcx> { + /// The type of the state "discriminant" used in the generator type. + pub fn discr_ty(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Ty<'tcx> { + tcx.types.u32 + } + /// This returns the types of the MIR locals which had to be stored across suspension points. /// It is calculated in rustc_mir::transform::generator::StateTransform. /// All the types here must be in the tuple in GeneratorInterior. @@ -484,15 +486,15 @@ impl<'a, 'gcx, 'tcx> GeneratorSubsts<'tcx> { /// 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. + /// It includes the upvars and the state discriminant. pub fn pre_transforms_tys(self, def_id: DefId, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> impl Iterator<Item=Ty<'tcx>> + 'a { - self.upvar_tys(def_id, tcx).chain(iter::once(tcx.types.u32)) + self.upvar_tys(def_id, tcx).chain(iter::once(self.discr_ty(tcx))) } /// 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. + /// It includes the upvars, state types and the state discriminant. pub fn field_tys(self, def_id: DefId, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> impl Iterator<Item=Ty<'tcx>> + Captures<'gcx> + 'a { diff --git a/src/librustc_mir/build/expr/as_rvalue.rs b/src/librustc_mir/build/expr/as_rvalue.rs index c58b570d8fc..0871217c524 100644 --- a/src/librustc_mir/build/expr/as_rvalue.rs +++ b/src/librustc_mir/build/expr/as_rvalue.rs @@ -255,15 +255,16 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> { let movability = movability.unwrap(); // Add the state operand since it follows the upvars in the generator // struct. See librustc_mir/transform/generator.rs for more details. + let discr_ty = substs.discr_ty(this.hir.tcx()); operands.push(Operand::Constant(box Constant { span: expr_span, - ty: this.hir.tcx().types.u32, + ty: discr_ty, user_ty: None, literal: this.hir.tcx().mk_const( ty::Const::from_bits( this.hir.tcx(), 0, - ty::ParamEnv::empty().and(this.hir.tcx().types.u32), + ty::ParamEnv::empty().and(discr_ty), ), ), })); diff --git a/src/librustc_mir/transform/generator.rs b/src/librustc_mir/transform/generator.rs index 2b909feb960..cf7397ca488 100644 --- a/src/librustc_mir/transform/generator.rs +++ b/src/librustc_mir/transform/generator.rs @@ -166,6 +166,9 @@ struct TransformVisitor<'a, 'tcx: 'a> { // The index of the generator state in the generator struct state_field: usize, + // The type of the generator state in the generator struct + discr_ty: Ty<'tcx>, + // Mapping from Local to (type of local, generator struct index) // FIXME(eddyb) This should use `IndexVec<Local, Option<_>>`. remap: FxHashMap<Local, (Ty<'tcx>, usize)>, @@ -200,15 +203,15 @@ impl<'a, 'tcx> TransformVisitor<'a, 'tcx> { // Create a statement which changes the generator state fn set_state(&self, state_disc: u32, source_info: SourceInfo) -> Statement<'tcx> { - let state = self.make_field(self.state_field, self.tcx.types.u32); + let state = self.make_field(self.state_field, self.discr_ty); let val = Operand::Constant(box Constant { span: source_info.span, - ty: self.tcx.types.u32, + ty: self.discr_ty, user_ty: None, literal: self.tcx.mk_const(ty::Const::from_bits( self.tcx, state_disc.into(), - ty::ParamEnv::empty().and(self.tcx.types.u32) + ty::ParamEnv::empty().and(self.discr_ty) )), }); Statement { @@ -889,10 +892,11 @@ impl MirPass for StateTransform { let gen_ty = mir.local_decls.raw[1].ty; // Get the interior types and substs which typeck computed - let (upvars, interior, movable) = match gen_ty.sty { + let (upvars, interior, discr_ty, movable) = match gen_ty.sty { ty::Generator(_, substs, movability) => { (substs.upvar_tys(def_id, tcx).collect(), substs.witness(def_id, tcx), + substs.discr_ty(tcx), movability == hir::GeneratorMovability::Movable) } _ => bug!(), @@ -937,6 +941,7 @@ impl MirPass for StateTransform { suspension_points: Vec::new(), new_ret_local, state_field, + discr_ty, }; transform.visit_mir(mir); |