1 use rustc_ast::ast::Attribute;
3 use rustc_hir::def_id::LocalDefId;
4 use rustc_hir::itemlikevisit::ItemLikeVisitor;
5 use rustc_hir::ItemKind;
6 use rustc_middle::ty::layout::{HasParamEnv, HasTyCtxt, TyAndLayout};
7 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
8 use rustc_span::symbol::sym;
9 use rustc_target::abi::{HasDataLayout, LayoutOf, TargetDataLayout};
11 pub fn test_layout(tcx: TyCtxt<'_>) {
12 if tcx.features().rustc_attrs {
13 // if the `rustc_attrs` feature is not enabled, don't bother testing layout
14 tcx.hir().krate().visit_all_item_likes(&mut LayoutTest { tcx });
18 struct LayoutTest<'tcx> {
22 impl ItemLikeVisitor<'tcx> for LayoutTest<'tcx> {
23 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
24 let item_def_id = self.tcx.hir().local_def_id(item.hir_id);
29 | ItemKind::Struct(..)
31 | ItemKind::OpaqueTy(..) => {
32 for attr in self.tcx.get_attrs(item_def_id.to_def_id()).iter() {
33 if attr.check_name(sym::rustc_layout) {
34 self.dump_layout_of(item_def_id, item, attr);
42 fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem<'tcx>) {}
43 fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem<'tcx>) {}
46 impl LayoutTest<'tcx> {
47 fn dump_layout_of(&self, item_def_id: LocalDefId, item: &hir::Item<'tcx>, attr: &Attribute) {
49 let param_env = self.tcx.param_env(item_def_id);
50 let ty = self.tcx.type_of(item_def_id);
51 match self.tcx.layout_of(param_env.and(ty)) {
53 // Check out the `#[rustc_layout(..)]` attribute to tell what to dump.
54 // The `..` are the names of fields to dump.
55 let meta_items = attr.meta_item_list().unwrap_or_default();
56 for meta_item in meta_items {
57 match meta_item.name_or_empty() {
59 self.tcx.sess.span_err(item.span, &format!("abi: {:?}", ty_layout.abi));
65 .span_err(item.span, &format!("align: {:?}", ty_layout.align));
71 .span_err(item.span, &format!("size: {:?}", ty_layout.size));
74 sym::homogeneous_aggregate => {
75 self.tcx.sess.span_err(
78 "homogeneous_aggregate: {:?}",
80 .homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env }),
86 self.tcx.sess.span_err(
88 &format!("layout_of({:?}) = {:#?}", ty, *ty_layout),
93 self.tcx.sess.span_err(
95 &format!("unrecognized field name `{}`", name),
102 Err(layout_error) => {
103 self.tcx.sess.span_err(item.span, &format!("layout error: {:?}", layout_error));
109 struct UnwrapLayoutCx<'tcx> {
111 param_env: ParamEnv<'tcx>,
114 impl LayoutOf for UnwrapLayoutCx<'tcx> {
116 type TyAndLayout = TyAndLayout<'tcx>;
118 fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyAndLayout {
119 self.tcx.layout_of(self.param_env.and(ty)).unwrap()
123 impl HasTyCtxt<'tcx> for UnwrapLayoutCx<'tcx> {
124 fn tcx(&self) -> TyCtxt<'tcx> {
129 impl HasParamEnv<'tcx> for UnwrapLayoutCx<'tcx> {
130 fn param_env(&self) -> ParamEnv<'tcx> {
135 impl HasDataLayout for UnwrapLayoutCx<'tcx> {
136 fn data_layout(&self) -> &TargetDataLayout {
137 self.tcx.data_layout()