add logic to check allocator matching

This commit is contained in:
Jacherr 2023-11-08 18:27:33 +00:00
parent 73b9841a3e
commit 3a91a11740

View file

@ -23,6 +23,8 @@ pub(super) fn check(
if let Some(last) = last_path_segment(qpath).args
// Get the _ part of Vec<_>
&& let Some(GenericArg::Type(ty)) = last.args.first()
// extract allocator from the Vec for later
&& let vec_alloc_ty = last.args.get(1)
// ty is now _ at this point
&& let TyKind::Path(ref ty_qpath) = ty.kind
&& let res = cx.qpath_res(ty_qpath, ty.hir_id)
@ -30,12 +32,23 @@ pub(super) fn check(
&& Some(def_id) == cx.tcx.lang_items().owned_box()
// At this point, we know ty is Box<T>, now get T
&& let Some(last) = last_path_segment(ty_qpath).args
// extract allocator from thr Box for later
&& let Some(GenericArg::Type(boxed_ty)) = last.args.first()
&& let boxed_alloc_ty = last.args.get(1)
&& let ty_ty = hir_ty_to_ty(cx.tcx, boxed_ty)
&& !ty_ty.has_escaping_bound_vars()
&& ty_ty.is_sized(cx.tcx, cx.param_env)
&& let Ok(ty_ty_size) = cx.layout_of(ty_ty).map(|l| l.size.bytes())
&& ty_ty_size < box_size_threshold
// https://github.com/rust-lang/rust-clippy/issues/7114
// this code also does not consider that Global can be explicitly
// defined (yet) as in Vec<_, Global> so a very slight false negative edge case
&& match (vec_alloc_ty, boxed_alloc_ty) {
(None, None) => true,
(Some(GenericArg::Type(l)), Some(GenericArg::Type(r))) =>
hir_ty_to_ty(cx.tcx, l) == hir_ty_to_ty(cx.tcx, r),
_ => false
}
{
span_lint_and_sugg(
cx,