use rustc_hir as hir;
use rustc_hir::intravisit;
use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::hir::map::Map;
use rustc_middle::lint::in_external_macro;
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
}
impl<'a, 'tcx> intravisit::Visitor<'tcx> for MutVisitor<'a, 'tcx> {
- type Map = Map<'tcx>;
-
fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
if in_external_macro(self.cx.sess(), expr.span) {
return;
expr.span,
"generally you want to avoid `&mut &mut _` if possible",
);
- } else if let ty::Ref(_, _, hir::Mutability::Mut) = self.cx.typeck_results().expr_ty(e).kind() {
- span_lint(
- self.cx,
- MUT_MUT,
- expr.span,
- "this expression mutably borrows a mutable reference. Consider reborrowing",
- );
+ } else if let ty::Ref(_, ty, hir::Mutability::Mut) = self.cx.typeck_results().expr_ty(e).kind() {
+ if ty.peel_refs().is_sized(self.cx.tcx, self.cx.param_env) {
+ span_lint(
+ self.cx,
+ MUT_MUT,
+ expr.span,
+ "this expression mutably borrows a mutable reference. Consider reborrowing",
+ );
+ }
}
}
}
intravisit::walk_ty(self, ty);
}
- fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
- intravisit::NestedVisitorMap::None
- }
}