clippy_lints/src/types/rc_mutex.rs

   1 use clippy_utils::diagnostics::span_lint_and_help;
   2 use clippy_utils::{path_def_id, qpath_generic_tys};
   3 use if_chain::if_chain;
   4 use rustc_hir::{self as hir, def_id::DefId, QPath};
   5 use rustc_lint::LateContext;
   6 use rustc_span::symbol::sym;
   7
   8 use super::RC_MUTEX;
   9
  10 pub(super) fn check(cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>, qpath: &QPath<'_>, def_id: DefId) -> bool {
  11     if_chain! {
  12         if cx.tcx.is_diagnostic_item(sym::Rc, def_id) ;
  13         if let Some(arg) = qpath_generic_tys(qpath).next();
  14         if let Some(id) = path_def_id(cx, arg);
  15         if cx.tcx.is_diagnostic_item(sym::Mutex, id);
  16         then {
  17             span_lint_and_help(
  18                 cx,
  19                 RC_MUTEX,
  20                 hir_ty.span,
  21                 "usage of `Rc<Mutex<_>>`",
  22                 None,
  23                 "consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead",
  24             );
  25             return true;
  26         }
  27     }
  28
  29     false
  30 }