2 use rustc::hir::def_id::DefId;
3 use rustc::hir::itemlikevisit::ItemLikeVisitor;
4 use rustc::hir::ItemKind;
5 use rustc::ty::layout::HasDataLayout;
6 use rustc::ty::layout::HasTyCtxt;
7 use rustc::ty::layout::LayoutOf;
8 use rustc::ty::layout::TargetDataLayout;
9 use rustc::ty::layout::TyLayout;
10 use rustc::ty::layout::HasParamEnv;
11 use rustc::ty::ParamEnv;
13 use rustc::ty::TyCtxt;
14 use syntax::ast::Attribute;
15 use syntax::symbol::sym;
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
22 .visit_all_item_likes(&mut VarianceTest { tcx });
26 struct VarianceTest<'tcx> {
30 impl ItemLikeVisitor<'tcx> for VarianceTest<'tcx> {
31 fn visit_item(&mut self, item: &'tcx hir::Item) {
32 let item_def_id = self.tcx.hir().local_def_id(item.hir_id);
34 if let ItemKind::TyAlias(..) = item.kind {
35 for attr in self.tcx.get_attrs(item_def_id).iter() {
36 if attr.check_name(sym::rustc_layout) {
37 self.dump_layout_of(item_def_id, item, attr);
43 fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem) {}
44 fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem) {}
47 impl VarianceTest<'tcx> {
48 fn dump_layout_of(&self, item_def_id: DefId, item: &hir::Item, attr: &Attribute) {
50 let param_env = self.tcx.param_env(item_def_id);
51 let ty = self.tcx.type_of(item_def_id);
52 match self.tcx.layout_of(param_env.and(ty)) {
54 // Check out the `#[rustc_layout(..)]` attribute to tell what to dump.
55 // The `..` are the names of fields to dump.
56 let meta_items = attr.meta_item_list().unwrap_or_default();
57 for meta_item in meta_items {
58 match meta_item.name_or_empty() {
62 .span_err(item.span, &format!("abi: {:?}", ty_layout.abi));
68 .span_err(item.span, &format!("align: {:?}", ty_layout.align));
74 .span_err(item.span, &format!("size: {:?}", ty_layout.size));
77 sym::homogeneous_aggregate => {
78 self.tcx.sess.span_err(
81 "homogeneous_aggregate: {:?}",
83 .homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env }),
89 self.tcx.sess.span_err(
91 &format!("unrecognized field name `{}`", name),
98 Err(layout_error) => {
101 .span_err(item.span, &format!("layout error: {:?}", layout_error));
107 struct UnwrapLayoutCx<'tcx> {
109 param_env: ParamEnv<'tcx>,
112 impl LayoutOf for UnwrapLayoutCx<'tcx> {
114 type TyLayout = TyLayout<'tcx>;
116 fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
117 self.tcx.layout_of(self.param_env.and(ty)).unwrap()
121 impl HasTyCtxt<'tcx> for UnwrapLayoutCx<'tcx> {
122 fn tcx(&self) -> TyCtxt<'tcx> {
127 impl HasParamEnv<'tcx> for UnwrapLayoutCx<'tcx> {
128 fn param_env(&self) -> ParamEnv<'tcx> {
133 impl HasDataLayout for UnwrapLayoutCx<'tcx> {
134 fn data_layout(&self) -> &TargetDataLayout {
135 self.tcx.data_layout()