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use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::paths;
use clippy_utils::source::snippet_with_macro_callsite;
use clippy_utils::ty::{is_type_diagnostic_item, match_type};
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_middle::ty;
use rustc_span::symbol::{sym, Symbol};
use super::CLONE_ON_REF_PTR;
pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, method_name: Symbol, args: &[hir::Expr<'_>]) {
if !(args.len() == 1 && method_name == sym::clone) {
return;
}
let arg = &args[0];
let obj_ty = cx.typeck_results().expr_ty(arg).peel_refs();
if let ty::Adt(_, subst) = obj_ty.kind() {
let caller_type = if is_type_diagnostic_item(cx, obj_ty, sym::Rc) {
"Rc"
} else if is_type_diagnostic_item(cx, obj_ty, sym::Arc) {
"Arc"
} else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) {
"Weak"
} else {
return;
};
let snippet = snippet_with_macro_callsite(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),
Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak
);
}
}
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