1 use clippy_utils::diagnostics::span_lint;
2 use clippy_utils::macros::{find_assert_eq_args, root_macro_call_first_node};
3 use rustc_hir::intravisit::{walk_expr, Visitor};
4 use rustc_hir::{BorrowKind, Expr, ExprKind, MatchSource, Mutability};
5 use rustc_lint::{LateContext, LateLintPass};
6 use rustc_middle::hir::nested_filter;
8 use rustc_session::{declare_lint_pass, declare_tool_lint};
11 declare_clippy_lint! {
13 /// Checks for function/method calls with a mutable
14 /// parameter in `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` macros.
16 /// ### Why is this bad?
17 /// In release builds `debug_assert!` macros are optimized out by the
19 /// Therefore mutating something in a `debug_assert!` macro results in different behavior
20 /// between a release and debug build.
24 /// debug_assert_eq!(vec![3].pop(), Some(3));
29 /// # fn takes_a_mut_parameter(_: &mut u32) -> bool { unimplemented!() }
30 /// debug_assert!(takes_a_mut_parameter(&mut x));
32 #[clippy::version = "1.40.0"]
33 pub DEBUG_ASSERT_WITH_MUT_CALL,
35 "mutable arguments in `debug_assert{,_ne,_eq}!`"
38 declare_lint_pass!(DebugAssertWithMutCall => [DEBUG_ASSERT_WITH_MUT_CALL]);
40 impl<'tcx> LateLintPass<'tcx> for DebugAssertWithMutCall {
41 fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
42 let Some(macro_call) = root_macro_call_first_node(cx, e) else { return };
43 let macro_name = cx.tcx.item_name(macro_call.def_id);
46 "debug_assert" | "debug_assert_eq" | "debug_assert_ne"
50 let Some((lhs, rhs, _)) = find_assert_eq_args(cx, e, macro_call.expn) else { return };
51 for arg in [lhs, rhs] {
52 let mut visitor = MutArgVisitor::new(cx);
53 visitor.visit_expr(arg);
54 if let Some(span) = visitor.expr_span() {
57 DEBUG_ASSERT_WITH_MUT_CALL,
59 &format!("do not call a function with mutable arguments inside of `{macro_name}!`"),
66 struct MutArgVisitor<'a, 'tcx> {
67 cx: &'a LateContext<'tcx>,
68 expr_span: Option<Span>,
72 impl<'a, 'tcx> MutArgVisitor<'a, 'tcx> {
73 fn new(cx: &'a LateContext<'tcx>) -> Self {
81 fn expr_span(&self) -> Option<Span> {
82 if self.found { self.expr_span } else { None }
86 impl<'a, 'tcx> Visitor<'tcx> for MutArgVisitor<'a, 'tcx> {
87 type NestedFilter = nested_filter::OnlyBodies;
89 fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
91 ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) => {
99 ExprKind::Path(_) => {
100 if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id) {
103 .any(|a| matches!(a.target.kind(), ty::Ref(_, _, Mutability::Mut)))
110 // Don't check await desugars
111 ExprKind::Match(_, _, MatchSource::AwaitDesugar) => return,
112 _ if !self.found => self.expr_span = Some(expr.span),
115 walk_expr(self, expr);
118 fn nested_visit_map(&mut self) -> Self::Map {