mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge method, type and const object safety checks

Browse Source
This commit is contained in:
Oli Scherer 2023-06-05 15:32:23 +00:00
parent 604ffab063
commit 58972d19e7
2 changed files with 47 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
compiler/rustc_hir_analysis/src/astconv/mod.rs
View File

@ -1643,6 +1643,10 @@ trait here instead: `trait NewTrait: {} {{}}`",
}
}
// `dyn Trait<Assoc = Foo>` desugars to (not Rust syntax) `dyn Trait where <Self as Trait>::Assoc = Foo`.
// So every `Projection` clause is an `Assoc = Foo` bound. `associated_types` contains all associated
// types's `DefId`, so the following loop removes all the `DefIds` of the associated types that have a
// corresponding `Projection` clause
for (projection_bound, _) in &projection_bounds {
for def_ids in associated_types.values_mut() {
def_ids.remove(&projection_bound.projection_def_id());

80
compiler/rustc_trait_selection/src/traits/object_safety.rs
View File

@ -115,15 +115,11 @@ fn object_safety_violations_for_trait(
tcx: TyCtxt<'_>,
trait_def_id: DefId,
) -> Vec<ObjectSafetyViolation> {
// Check methods for violations.
// Check assoc items for violations.
let mut violations: Vec<_> = tcx
.associated_items(trait_def_id)
.in_definition_order()
.filter(|item| item.kind == ty::AssocKind::Fn)
.filter_map(|&item| {
object_safety_violation_for_method(tcx, trait_def_id, item)
.map(|(code, span)| ObjectSafetyViolation::Method(item.name, code, span))
})
.filter_map(|&item| object_safety_violation_for_assoc_item(tcx, trait_def_id, item))
.collect();
// Check the trait itself.
@ -145,30 +141,6 @@ fn object_safety_violations_for_trait(
violations.push(ObjectSafetyViolation::SupertraitNonLifetimeBinder(spans));
}
violations.extend(
tcx.associated_items(trait_def_id)
.in_definition_order()
.filter(|item| item.kind == ty::AssocKind::Const)
.map(|item| {
let ident = item.ident(tcx);
ObjectSafetyViolation::AssocConst(ident.name, ident.span)
}),
);
if !tcx.features().generic_associated_types_extended {
violations.extend(
tcx.associated_items(trait_def_id)
.in_definition_order()
.filter(|item| item.kind == ty::AssocKind::Type)
.filter(|item| !tcx.generics_of(item.def_id).params.is_empty())
.filter(|item| item.opt_rpitit_info.is_none())
.map(|item| {
let ident = item.ident(tcx);
ObjectSafetyViolation::GAT(ident.name, ident.span)
}),
);
}
debug!(
"object_safety_violations_for_trait(trait_def_id={:?}) = {:?}",
trait_def_id, violations
@ -401,34 +373,54 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
})
}
/// Returns `Some(_)` if this method makes the containing trait not object safe.
fn object_safety_violation_for_method(
/// Returns `Some(_)` if this item makes the containing trait not object safe.
#[instrument(level = "debug", skip(tcx), ret)]
fn object_safety_violation_for_assoc_item(
tcx: TyCtxt<'_>,
trait_def_id: DefId,
method: ty::AssocItem,
) -> Option<(MethodViolationCode, Span)> {
debug!("object_safety_violation_for_method({:?}, {:?})", trait_def_id, method);
// Any method that has a `Self : Sized` requisite is otherwise
item: ty::AssocItem,
) -> Option<ObjectSafetyViolation> {
// Any item that has a `Self : Sized` requisite is otherwise
// exempt from the regulations.
if generics_require_sized_self(tcx, method.def_id) {
if generics_require_sized_self(tcx, item.def_id) {
return None;
}
let violation = virtual_call_violation_for_method(tcx, trait_def_id, method);
match item.kind {
// Associated consts are never object safe, as they can't have `where` bounds yet at all,
// and associated const bounds in trait objects aren't a thing yet either.
ty::AssocKind::Const => {
Some(ObjectSafetyViolation::AssocConst(item.name, item.ident(tcx).span))
}
ty::AssocKind::Fn => virtual_call_violation_for_method(tcx, trait_def_id, item).map(|v| {
let node = tcx.hir().get_if_local(item.def_id);
// Get an accurate span depending on the violation.
violation.map(|v| {
let node = tcx.hir().get_if_local(method.def_id);
let span = match (&v, node) {
(MethodViolationCode::ReferencesSelfInput(Some(span)), _) => *span,
(MethodViolationCode::UndispatchableReceiver(Some(span)), _) => *span,
(MethodViolationCode::ReferencesImplTraitInTrait(span), _) => *span,
(MethodViolationCode::ReferencesSelfOutput, Some(node)) => {
node.fn_decl().map_or(method.ident(tcx).span, |decl| decl.output.span())
node.fn_decl().map_or(item.ident(tcx).span, |decl| decl.output.span())
}
_ => method.ident(tcx).span,
_ => item.ident(tcx).span,
};
(v, span)
})
ObjectSafetyViolation::Method(item.name, v, span)
}),
// Associated types can only be object safe if they have `Self: Sized` bounds.
ty::AssocKind::Type => {
if !tcx.features().generic_associated_types_extended
&& !tcx.generics_of(item.def_id).params.is_empty()
&& item.opt_rpitit_info.is_none()
{
Some(ObjectSafetyViolation::GAT(item.name, item.ident(tcx).span))
} else {
// We will permit associated types if they are explicitly mentioned in the trait object.
// We can't check this here, as here we only check if it is guaranteed to not be possible.
None
}
}
}
}
/// Returns `Some(_)` if this method cannot be called on a trait