1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
use crate::methods::TYPE_ID_ON_BOX;
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::source::snippet;
use rustc_errors::Applicability;
use rustc_hir::Expr;
use rustc_lint::LateContext;
use rustc_middle::ty::adjustment::{Adjust, Adjustment};
use rustc_middle::ty::{self, ExistentialPredicate, Ty};
use rustc_span::{sym, Span};
fn is_dyn_any(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
if let ty::Dynamic(preds, ..) = ty.kind() {
preds.iter().any(|p| match p.skip_binder() {
ExistentialPredicate::Trait(tr) => cx.tcx.is_diagnostic_item(sym::Any, tr.def_id),
_ => false,
})
} else {
false
}
}
pub(super) fn check(cx: &LateContext<'_>, receiver: &Expr<'_>, call_span: Span) {
let recv_adjusts = cx.typeck_results().expr_adjustments(receiver);
if let Some(Adjustment { target: recv_ty, .. }) = recv_adjusts.last()
&& let ty::Ref(_, ty, _) = recv_ty.kind()
&& let ty::Adt(adt, args) = ty.kind()
&& adt.is_box()
&& is_dyn_any(cx, args.type_at(0))
{
span_lint_and_then(
cx,
TYPE_ID_ON_BOX,
call_span,
"calling `.type_id()` on a `Box<dyn Any>`",
|diag| {
let derefs = recv_adjusts
.iter()
.filter(|adj| matches!(adj.kind, Adjust::Deref(None)))
.count();
let mut sugg = "*".repeat(derefs + 1);
sugg += &snippet(cx, receiver.span, "<expr>");
diag.note(
"this returns the type id of the literal type `Box<dyn Any>` instead of the \
type id of the boxed value, which is most likely not what you want",
)
.note(
"if this is intentional, use `TypeId::of::<Box<dyn Any>>()` instead, \
which makes it more clear",
)
.span_suggestion(
receiver.span,
"consider dereferencing first",
format!("({sugg})"),
Applicability::MaybeIncorrect,
);
},
);
}
}
|
