rust/compiler/rustc_passes/src/layout_test.rs
2021-12-15 20:12:53 -07:00

147 lines
5.0 KiB
Rust

use rustc_ast::Attribute;
use rustc_hir as hir;
use rustc_hir::def_id::LocalDefId;
use rustc_hir::itemlikevisit::ItemLikeVisitor;
use rustc_hir::ItemKind;
use rustc_middle::ty::layout::{HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
use rustc_span::symbol::sym;
use rustc_span::Span;
use rustc_target::abi::{HasDataLayout, TargetDataLayout};
pub fn test_layout(tcx: TyCtxt<'_>) {
if tcx.features().rustc_attrs {
// if the `rustc_attrs` feature is not enabled, don't bother testing layout
tcx.hir().visit_all_item_likes(&mut LayoutTest { tcx });
}
}
struct LayoutTest<'tcx> {
tcx: TyCtxt<'tcx>,
}
impl<'tcx> ItemLikeVisitor<'tcx> for LayoutTest<'tcx> {
fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
match item.kind {
ItemKind::TyAlias(..)
| ItemKind::Enum(..)
| ItemKind::Struct(..)
| ItemKind::Union(..) => {
for attr in self.tcx.get_attrs(item.def_id.to_def_id()).iter() {
if attr.has_name(sym::rustc_layout) {
self.dump_layout_of(item.def_id, item, attr);
}
}
}
_ => {}
}
}
fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem<'tcx>) {}
fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem<'tcx>) {}
fn visit_foreign_item(&mut self, _: &'tcx hir::ForeignItem<'tcx>) {}
}
impl<'tcx> LayoutTest<'tcx> {
fn dump_layout_of(&self, item_def_id: LocalDefId, item: &hir::Item<'tcx>, attr: &Attribute) {
let tcx = self.tcx;
let param_env = self.tcx.param_env(item_def_id);
let ty = self.tcx.type_of(item_def_id);
match self.tcx.layout_of(param_env.and(ty)) {
Ok(ty_layout) => {
// Check out the `#[rustc_layout(..)]` attribute to tell what to dump.
// The `..` are the names of fields to dump.
let meta_items = attr.meta_item_list().unwrap_or_default();
for meta_item in meta_items {
match meta_item.name_or_empty() {
sym::abi => {
self.tcx.sess.span_err(item.span, &format!("abi: {:?}", ty_layout.abi));
}
sym::align => {
self.tcx
.sess
.span_err(item.span, &format!("align: {:?}", ty_layout.align));
}
sym::size => {
self.tcx
.sess
.span_err(item.span, &format!("size: {:?}", ty_layout.size));
}
sym::homogeneous_aggregate => {
self.tcx.sess.span_err(
item.span,
&format!(
"homogeneous_aggregate: {:?}",
ty_layout
.homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env }),
),
);
}
sym::debug => {
let normalized_ty = self.tcx.normalize_erasing_regions(
param_env.with_reveal_all_normalized(self.tcx),
ty,
);
self.tcx.sess.span_err(
item.span,
&format!("layout_of({:?}) = {:#?}", normalized_ty, *ty_layout),
);
}
name => {
self.tcx.sess.span_err(
meta_item.span(),
&format!("unrecognized field name `{}`", name),
);
}
}
}
}
Err(layout_error) => {
self.tcx.sess.span_err(item.span, &format!("layout error: {:?}", layout_error));
}
}
}
}
struct UnwrapLayoutCx<'tcx> {
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
}
impl<'tcx> LayoutOfHelpers<'tcx> for UnwrapLayoutCx<'tcx> {
type LayoutOfResult = TyAndLayout<'tcx>;
fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
span_bug!(
span,
"`#[rustc_layout(..)]` test resulted in `layout_of({}) = Err({})`",
ty,
err
);
}
}
impl<'tcx> HasTyCtxt<'tcx> for UnwrapLayoutCx<'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx
}
}
impl<'tcx> HasParamEnv<'tcx> for UnwrapLayoutCx<'tcx> {
fn param_env(&self) -> ParamEnv<'tcx> {
self.param_env
}
}
impl<'tcx> HasDataLayout for UnwrapLayoutCx<'tcx> {
fn data_layout(&self) -> &TargetDataLayout {
self.tcx.data_layout()
}
}