Make Ty::boxed_ty return an Option

This commit is contained in:
Pavel Grigorenko 2024-09-05 00:34:04 +03:00
parent 842d6fc32e
commit f6e8a84eea
21 changed files with 58 additions and 48 deletions

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@ -662,9 +662,10 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, '_, 'tcx> {
// `&dyn Trait`
ty::Ref(_, ty, _) if ty.is_trait() => true,
// `Box<dyn Trait>`
_ if ty.is_box() && ty.boxed_ty().is_trait() => {
_ if ty.boxed_ty().is_some_and(Ty::is_trait) => {
true
}
// `dyn Trait`
_ if ty.is_trait() => true,
// Anything else.

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@ -345,9 +345,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
variant_index: Option<VariantIdx>,
including_tuple_field: IncludingTupleField,
) -> Option<String> {
if ty.is_box() {
if let Some(boxed_ty) = ty.boxed_ty() {
// If the type is a box, the field is described from the boxed type
self.describe_field_from_ty(ty.boxed_ty(), field, variant_index, including_tuple_field)
self.describe_field_from_ty(boxed_ty, field, variant_index, including_tuple_field)
} else {
match *ty.kind() {
ty::Adt(def, _) => {

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@ -456,7 +456,7 @@ pub(crate) fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) ->
if def.is_box()
&& args.get(1).map_or(true, |arg| cx.layout_of(arg.expect_ty()).is_1zst()) =>
{
build_pointer_or_reference_di_node(cx, t, t.boxed_ty(), unique_type_id)
build_pointer_or_reference_di_node(cx, t, t.expect_boxed_ty(), unique_type_id)
}
ty::FnDef(..) | ty::FnPtr(..) => build_subroutine_type_di_node(cx, unique_type_id),
ty::Closure(..) => build_closure_env_di_node(cx, unique_type_id),

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@ -189,7 +189,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
ty::Ref(_, ty, _) => *ty,
ty::RawPtr(ty, _) => *ty,
// We only accept `Box` with the default allocator.
_ if ty.is_box_global(*self.tcx) => ty.boxed_ty(),
_ if ty.is_box_global(*self.tcx) => ty.expect_boxed_ty(),
_ => return Ok(None),
}))
};

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@ -63,8 +63,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// Instead, the problem is that the array-into_iter hack will no longer
// apply in Rust 2021.
(ARRAY_INTO_ITER, "2021")
} else if self_ty.is_box()
&& self_ty.boxed_ty().is_slice()
} else if self_ty.boxed_ty().is_some_and(Ty::is_slice)
&& !span.at_least_rust_2024()
{
// In this case, it wasn't really a prelude addition that was the problem.

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@ -1485,8 +1485,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
// Some trait methods are excluded for boxed slices before 2024.
// (`boxed_slice.into_iter()` wants a slice iterator for compatibility.)
if self_ty.is_box()
&& self_ty.boxed_ty().is_slice()
if self_ty.boxed_ty().is_some_and(Ty::is_slice)
&& !method_name.span.at_least_rust_2024()
{
let trait_def = self.tcx.trait_def(poly_trait_ref.def_id());

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@ -94,12 +94,9 @@ impl<'tcx> LateLintPass<'tcx> for ShadowedIntoIter {
fn is_ref_to_array(ty: Ty<'_>) -> bool {
if let ty::Ref(_, pointee_ty, _) = *ty.kind() { pointee_ty.is_array() } else { false }
}
fn is_boxed_slice(ty: Ty<'_>) -> bool {
ty.is_box() && ty.boxed_ty().is_slice()
}
fn is_ref_to_boxed_slice(ty: Ty<'_>) -> bool {
if let ty::Ref(_, pointee_ty, _) = *ty.kind() {
is_boxed_slice(pointee_ty)
pointee_ty.boxed_ty().is_some_and(Ty::is_slice)
} else {
false
}
@ -119,7 +116,7 @@ impl<'tcx> LateLintPass<'tcx> for ShadowedIntoIter {
.iter()
.copied()
.take_while(|ty| !is_ref_to_boxed_slice(*ty))
.position(|ty| is_boxed_slice(ty))
.position(|ty| ty.boxed_ty().is_some_and(Ty::is_slice))
{
(BOXED_SLICE_INTO_ITER, "Box<[T]>", "2024", idx == 0)
} else {

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@ -1304,8 +1304,10 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
match *ty.kind() {
ty::Adt(def, args) => {
if def.is_box() && matches!(self.mode, CItemKind::Definition) {
if ty.boxed_ty().is_sized(tcx, self.cx.param_env) {
if let Some(boxed) = ty.boxed_ty()
&& matches!(self.mode, CItemKind::Definition)
{
if boxed.is_sized(tcx, self.cx.param_env) {
return FfiSafe;
} else {
return FfiUnsafe {

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@ -283,9 +283,8 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
}
match *ty.kind() {
ty::Adt(..) if ty.is_box() => {
let boxed_ty = ty.boxed_ty();
is_ty_must_use(cx, boxed_ty, expr, span)
ty::Adt(..) if let Some(boxed) = ty.boxed_ty() => {
is_ty_must_use(cx, boxed, expr, span)
.map(|inner| MustUsePath::Boxed(Box::new(inner)))
}
ty::Adt(def, args) if cx.tcx.is_lang_item(def.did(), LangItem::Pin) => {

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@ -1075,11 +1075,13 @@ where
// the raw pointer, so size and align are set to the boxed type, but `pointee.safe`
// will still be `None`.
if let Some(ref mut pointee) = result {
if offset.bytes() == 0 && this.ty.is_box() {
if offset.bytes() == 0
&& let Some(boxed_ty) = this.ty.boxed_ty()
{
debug_assert!(pointee.safe.is_none());
let optimize = tcx.sess.opts.optimize != OptLevel::No;
pointee.safe = Some(PointerKind::Box {
unpin: optimize && this.ty.boxed_ty().is_unpin(tcx, cx.param_env()),
unpin: optimize && boxed_ty.is_unpin(tcx, cx.param_env()),
global: this.ty.is_box_global(tcx),
});
}

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@ -1170,14 +1170,19 @@ impl<'tcx> Ty<'tcx> {
}
}
/// Panics if called on any type other than `Box<T>`.
pub fn boxed_ty(self) -> Ty<'tcx> {
pub fn boxed_ty(self) -> Option<Ty<'tcx>> {
match self.kind() {
Adt(def, args) if def.is_box() => args.type_at(0),
_ => bug!("`boxed_ty` is called on non-box type {:?}", self),
Adt(def, args) if def.is_box() => Some(args.type_at(0)),
_ => None,
}
}
/// Panics if called on any type other than `Box<T>`.
pub fn expect_boxed_ty(self) -> Ty<'tcx> {
self.boxed_ty()
.unwrap_or_else(|| bug!("`expect_boxed_ty` is called on non-box type {:?}", self))
}
/// A scalar type is one that denotes an atomic datum, with no sub-components.
/// (A RawPtr is scalar because it represents a non-managed pointer, so its
/// contents are abstract to rustc.)
@ -1323,7 +1328,7 @@ impl<'tcx> Ty<'tcx> {
/// Some types -- notably unsafe ptrs -- can only be dereferenced explicitly.
pub fn builtin_deref(self, explicit: bool) -> Option<Ty<'tcx>> {
match *self.kind() {
Adt(def, _) if def.is_box() => Some(self.boxed_ty()),
_ if let Some(boxed) = self.boxed_ty() => Some(boxed),
Ref(_, ty, _) => Some(ty),
RawPtr(ty, _) if explicit => Some(ty),
_ => None,

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@ -1628,7 +1628,7 @@ impl<'tcx> ExplicitSelf<'tcx> {
_ if is_self_ty(self_arg_ty) => ByValue,
ty::Ref(region, ty, mutbl) if is_self_ty(ty) => ByReference(region, mutbl),
ty::RawPtr(ty, mutbl) if is_self_ty(ty) => ByRawPointer(mutbl),
ty::Adt(def, _) if def.is_box() && is_self_ty(self_arg_ty.boxed_ty()) => ByBox,
_ if self_arg_ty.boxed_ty().is_some_and(is_self_ty) => ByBox,
_ => Other,
}
}

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@ -62,11 +62,13 @@ impl<'tcx, 'a> MutVisitor<'tcx> for ElaborateBoxDerefVisitor<'tcx, 'a> {
let base_ty = self.local_decls[place.local].ty;
// Derefer ensures that derefs are always the first projection
if place.projection.first() == Some(&PlaceElem::Deref) && base_ty.is_box() {
if let Some(PlaceElem::Deref) = place.projection.first()
&& let Some(boxed_ty) = base_ty.boxed_ty()
{
let source_info = self.local_decls[place.local].source_info;
let (unique_ty, nonnull_ty, ptr_ty) =
build_ptr_tys(tcx, base_ty.boxed_ty(), self.unique_did, self.nonnull_did);
build_ptr_tys(tcx, boxed_ty, self.unique_did, self.nonnull_did);
let ptr_local = self.patch.new_temp(ptr_ty, source_info.span);
@ -120,13 +122,15 @@ impl<'tcx> MirPass<'tcx> for ElaborateBoxDerefs {
for (base, elem) in place.iter_projections() {
let base_ty = base.ty(&body.local_decls, tcx).ty;
if elem == PlaceElem::Deref && base_ty.is_box() {
if let PlaceElem::Deref = elem
&& let Some(boxed_ty) = base_ty.boxed_ty()
{
// Clone the projections before us, since now we need to mutate them.
let new_projections =
new_projections.get_or_insert_with(|| base.projection.to_vec());
let (unique_ty, nonnull_ty, ptr_ty) =
build_ptr_tys(tcx, base_ty.boxed_ty(), unique_did, nonnull_did);
build_ptr_tys(tcx, boxed_ty, unique_did, nonnull_did);
new_projections.extend_from_slice(&build_projection(
unique_ty, nonnull_ty, ptr_ty,

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@ -1041,8 +1041,11 @@ fn find_vtable_types_for_unsizing<'tcx>(
match (source_ty.kind(), target_ty.kind()) {
(&ty::Ref(_, a, _), &ty::Ref(_, b, _) | &ty::RawPtr(b, _))
| (&ty::RawPtr(a, _), &ty::RawPtr(b, _)) => ptr_vtable(a, b),
(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
ptr_vtable(source_ty.boxed_ty(), target_ty.boxed_ty())
(_, _)
if let Some(source_boxed) = source_ty.boxed_ty()
&& let Some(target_boxed) = target_ty.boxed_ty() =>
{
ptr_vtable(source_boxed, target_boxed)
}
// T as dyn* Trait

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@ -1,5 +1,7 @@
// tidy-alphabetical-start
#![feature(array_windows)]
#![feature(if_let_guard)]
#![feature(let_chains)]
#![warn(unreachable_pub)]
// tidy-alphabetical-end

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@ -348,8 +348,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
}
}
if let Some(ty::error::ExpectedFound { found, .. }) = exp_found
&& ty.is_box()
&& ty.boxed_ty() == found
&& ty.boxed_ty() == Some(found)
&& let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
{
err.span_suggestion(

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@ -50,7 +50,7 @@ declare_clippy_lint! {
}
fn is_non_trait_box(ty: Ty<'_>) -> bool {
ty.is_box() && !ty.boxed_ty().is_trait()
ty.boxed_ty().is_some_and(|boxed| !boxed.is_trait())
}
struct EscapeDelegate<'a, 'tcx> {
@ -191,8 +191,8 @@ impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {
fn is_large_box(&self, ty: Ty<'tcx>) -> bool {
// Large types need to be boxed to avoid stack overflows.
if ty.is_box() {
self.cx.layout_of(ty.boxed_ty()).map_or(0, |l| l.size.bytes()) > self.too_large_for_stack
if let Some(boxed_ty) = ty.boxed_ty() {
self.cx.layout_of(boxed_ty).map_or(0, |l| l.size.bytes()) > self.too_large_for_stack
} else {
false
}

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@ -5187,8 +5187,8 @@ impl SelfKind {
fn matches_value<'a>(cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
if ty == parent_ty {
true
} else if ty.is_box() {
ty.boxed_ty() == parent_ty
} else if let Some(boxed_ty) = ty.boxed_ty() {
boxed_ty == parent_ty
} else if is_type_diagnostic_item(cx, ty, sym::Rc) || is_type_diagnostic_item(cx, ty, sym::Arc) {
if let ty::Adt(_, args) = ty.kind() {
args.types().next().map_or(false, |t| t == parent_ty)

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@ -16,7 +16,7 @@ pub(super) fn derefs_to_slice<'tcx>(
fn may_slice<'a>(cx: &LateContext<'a>, ty: Ty<'a>) -> bool {
match ty.kind() {
ty::Slice(_) => true,
ty::Adt(def, _) if def.is_box() => may_slice(cx, ty.boxed_ty()),
ty::Adt(..) if let Some(boxed) = ty.boxed_ty() => may_slice(cx, boxed),
ty::Adt(..) => is_type_diagnostic_item(cx, ty, sym::Vec),
ty::Array(_, size) => size.try_eval_target_usize(cx.tcx, cx.param_env).is_some(),
ty::Ref(_, inner, _) => may_slice(cx, *inner),
@ -33,7 +33,7 @@ pub(super) fn derefs_to_slice<'tcx>(
} else {
match ty.kind() {
ty::Slice(_) => Some(expr),
ty::Adt(def, _) if def.is_box() && may_slice(cx, ty.boxed_ty()) => Some(expr),
_ if ty.boxed_ty().is_some_and(|boxed| may_slice(cx, boxed)) => Some(expr),
ty::Ref(_, inner, _) => {
if may_slice(cx, *inner) {
Some(expr)

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@ -75,11 +75,9 @@ impl UnnecessaryBoxReturns {
.instantiate_bound_regions_with_erased(cx.tcx.fn_sig(def_id).skip_binder())
.output();
if !return_ty.is_box() {
let Some(boxed_ty) = return_ty.boxed_ty() else {
return;
}
let boxed_ty = return_ty.boxed_ty();
};
// It's sometimes useful to return Box<T> if T is unsized, so don't lint those.
// Also, don't lint if we know that T is very large, in which case returning

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@ -704,8 +704,8 @@ pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnS
/// If the type is function like, get the signature for it.
pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
if ty.is_box() {
return ty_sig(cx, ty.boxed_ty());
if let Some(boxed_ty) = ty.boxed_ty() {
return ty_sig(cx, boxed_ty);
}
match *ty.kind() {
ty::Closure(id, subs) => {