Fix incorrect suggestion when clone_on_ref_ptr is triggered in macros

This commit is contained in:
ThibsG 2020-08-24 14:01:27 +02:00
parent 27ae4d303c
commit 3d820f71fe
3 changed files with 32 additions and 7 deletions

View file

@ -2150,18 +2150,19 @@ fn lint_clone_on_ref_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::
return;
};
let snippet = if in_macro(arg.span) {
snippet_with_macro_callsite(cx, arg.span, "_")
} else {
snippet(cx, arg.span, "_")
};
span_lint_and_sugg(
cx,
CLONE_ON_REF_PTR,
expr.span,
"using `.clone()` on a ref-counted pointer",
"try this",
format!(
"{}::<{}>::clone(&{})",
caller_type,
subst.type_at(0),
snippet(cx, arg.span, "_")
),
format!("{}::<{}>::clone(&{})", caller_type, subst.type_at(0), snippet),
Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak
);
}

View file

@ -90,3 +90,21 @@ mod many_derefs {
let _ = &encoded.clone();
}
}
mod issue2076 {
use std::rc::Rc;
macro_rules! try_opt {
($expr: expr) => {
match $expr {
Some(value) => value,
None => return None,
}
};
}
fn func() -> Option<Rc<u8>> {
let rc = Rc::new(42);
Some(try_opt!(Some(rc)).clone())
}
}

View file

@ -96,5 +96,11 @@ help: or try being explicit if you are sure, that you want to clone a reference
LL | let _ = &<&[u8]>::clone(encoded);
| ^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 11 previous errors
error: using `.clone()` on a ref-counted pointer
--> $DIR/unnecessary_clone.rs:108:14
|
LL | Some(try_opt!(Some(rc)).clone())
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `Rc::<u8>::clone(&try_opt!(Some(rc)))`
error: aborting due to 12 previous errors