bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Don't ICE on unnormalized struct tail in layout computation

Browse source
This commit is contained in:
Michael Goulet 2023-06-19 19:57:44 +00:00
parent 3b2073f076
commit dd620aa73a
6 changed files with 65 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

20
compiler/rustc_ty_utils/src/layout.rs
View file

@ -145,17 +145,20 @@ fn layout_of_uncached<'tcx>(
return Ok(tcx.mk_layout(LayoutS::scalar(cx, data_ptr)));
}
let unsized_part = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type()
// Projection eagerly bails out when the pointee references errors,
// fall back to structurally deducing metadata.
&& !pointee.references_error()
{
let metadata_ty = tcx.normalize_erasing_regions(
let pointee_metadata = tcx.mk_projection(metadata_def_id, [pointee]);
let metadata_ty = match tcx.try_normalize_erasing_regions(
param_env,
tcx.mk_projection(metadata_def_id, [pointee]),
);
pointee_metadata,
) {
Ok(metadata_ty) => metadata_ty,
Err(err) => return Err(LayoutError::NormalizationFailure(pointee, err)),
};
let metadata_layout = cx.layout_of(metadata_ty)?;
// If the metadata is a 1-zst, then the pointer is thin.
if metadata_layout.is_zst() && metadata_layout.align.abi.bytes() == 1 {
@ -163,10 +166,13 @@ fn layout_of_uncached<'tcx>(
}
let Abi::Scalar(metadata) = metadata_layout.abi else {
return Err(LayoutError::Unknown(unsized_part));
return Err(LayoutError::Unknown(pointee));
};
metadata
} else {
let unsized_part = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
match unsized_part.kind() {
ty::Foreign(..) => {
return Ok(tcx.mk_layout(LayoutS::scalar(cx, data_ptr)));
@ -178,7 +184,7 @@ fn layout_of_uncached<'tcx>(
vtable
}
_ => {
return Err(LayoutError::Unknown(unsized_part));
return Err(LayoutError::Unknown(pointee));
}
}
};