1 use rustc::ty::layout::HasDataLayout;
2 use rustc::ty::layout::HasParamEnv;
3 use rustc::ty::layout::HasTyCtxt;
4 use rustc::ty::layout::LayoutOf;
5 use rustc::ty::layout::TargetDataLayout;
6 use rustc::ty::layout::TyLayout;
7 use rustc::ty::ParamEnv;
11 use rustc_hir::def_id::DefId;
12 use rustc_hir::itemlikevisit::ItemLikeVisitor;
13 use rustc_hir::ItemKind;
14 use rustc_span::symbol::sym;
15 use syntax::ast::Attribute;
17 pub fn test_layout(tcx: TyCtxt<'_>) {
18 if tcx.features().rustc_attrs {
19 // if the `rustc_attrs` feature is not enabled, don't bother testing layout
20 tcx.hir().krate().visit_all_item_likes(&mut VarianceTest { tcx });
24 struct VarianceTest<'tcx> {
28 impl ItemLikeVisitor<'tcx> for VarianceTest<'tcx> {
29 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
30 let item_def_id = self.tcx.hir().local_def_id(item.hir_id);
32 if let ItemKind::TyAlias(..) = item.kind {
33 for attr in self.tcx.get_attrs(item_def_id).iter() {
34 if attr.check_name(sym::rustc_layout) {
35 self.dump_layout_of(item_def_id, item, attr);
41 fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem<'tcx>) {}
42 fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem<'tcx>) {}
45 impl VarianceTest<'tcx> {
46 fn dump_layout_of(&self, item_def_id: DefId, item: &hir::Item<'tcx>, attr: &Attribute) {
48 let param_env = self.tcx.param_env(item_def_id);
49 let ty = self.tcx.type_of(item_def_id);
50 match self.tcx.layout_of(param_env.and(ty)) {
52 // Check out the `#[rustc_layout(..)]` attribute to tell what to dump.
53 // The `..` are the names of fields to dump.
54 let meta_items = attr.meta_item_list().unwrap_or_default();
55 for meta_item in meta_items {
56 match meta_item.name_or_empty() {
58 self.tcx.sess.span_err(item.span, &format!("abi: {:?}", ty_layout.abi));
64 .span_err(item.span, &format!("align: {:?}", ty_layout.align));
70 .span_err(item.span, &format!("size: {:?}", ty_layout.size));
73 sym::homogeneous_aggregate => {
74 self.tcx.sess.span_err(
77 "homogeneous_aggregate: {:?}",
79 .homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env }),
85 self.tcx.sess.span_err(
87 &format!("unrecognized field name `{}`", name),
94 Err(layout_error) => {
95 self.tcx.sess.span_err(item.span, &format!("layout error: {:?}", layout_error));
101 struct UnwrapLayoutCx<'tcx> {
103 param_env: ParamEnv<'tcx>,
106 impl LayoutOf for UnwrapLayoutCx<'tcx> {
108 type TyLayout = TyLayout<'tcx>;
110 fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
111 self.tcx.layout_of(self.param_env.and(ty)).unwrap()
115 impl HasTyCtxt<'tcx> for UnwrapLayoutCx<'tcx> {
116 fn tcx(&self) -> TyCtxt<'tcx> {
121 impl HasParamEnv<'tcx> for UnwrapLayoutCx<'tcx> {
122 fn param_env(&self) -> ParamEnv<'tcx> {
127 impl HasDataLayout for UnwrapLayoutCx<'tcx> {
128 fn data_layout(&self) -> &TargetDataLayout {
129 self.tcx.data_layout()