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CFI: Fix drop and drop_in_place

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Fix drop and drop_in_place by transforming self of drop and
drop_in_place methods into Drop trait objects.
This commit is contained in:
Ramon de C Valle 2024-03-25 21:39:26 -07:00
parent c98ea0d808
commit 0b860818e6
4 changed files with 79 additions and 2 deletions
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32
compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
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@ -1112,8 +1112,36 @@ pub fn typeid_for_instance<'tcx>(
mut instance: Instance<'tcx>,
options: TypeIdOptions,
) -> String {
if matches!(instance.def, ty::InstanceDef::Virtual(..)) {
instance.args = strip_receiver_auto(tcx, instance.args)
if (matches!(instance.def, ty::InstanceDef::Virtual(..))
&& Some(instance.def_id()) == tcx.lang_items().drop_in_place_fn())
|| matches!(instance.def, ty::InstanceDef::DropGlue(..))
{
// Adjust the type ids of DropGlues
//
// DropGlues may have indirect calls to one or more given types drop function. Rust allows
// for types to be erased to any trait object and retains the drop function for the original
// type, which means at the indirect call sites in DropGlues, when typeid_for_fnabi is
// called a second time, it only has information after type erasure and it could be a call
// on any arbitrary trait object. Normalize them to a synthesized Drop trait object, both on
// declaration/definition, and during code generation at call sites so they have the same
// type id and match.
//
// FIXME(rcvalle): This allows a drop call on any trait object to call the drop function of
// any other type.
//
let def_id = tcx
.lang_items()
.drop_trait()
.unwrap_or_else(|| bug!("typeid_for_instance: couldn't get drop_trait lang item"));
let predicate = ty::ExistentialPredicate::Trait(ty::ExistentialTraitRef {
def_id: def_id,
args: List::empty(),
});
let predicates = tcx.mk_poly_existential_predicates(&[ty::Binder::dummy(predicate)]);
let self_ty = Ty::new_dynamic(tcx, predicates, tcx.lifetimes.re_erased, ty::Dyn);
instance.args = tcx.mk_args_trait(self_ty, List::empty());
} else if matches!(instance.def, ty::InstanceDef::Virtual(..)) {
instance.args = strip_receiver_auto(tcx, instance.args);
}
if let Some(impl_id) = tcx.impl_of_method(instance.def_id())