1 use clippy_utils::diagnostics::span_lint;
2 use clippy_utils::{higher, is_direct_expn_of};
3 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
4 use rustc_hir::{BorrowKind, Expr, ExprKind, MatchSource, Mutability};
5 use rustc_lint::{LateContext, LateLintPass};
6 use rustc_middle::hir::map::Map;
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 behaviour
20 /// between a release and debug build.
24 /// debug_assert_eq!(vec![3].pop(), Some(3));
26 /// fn take_a_mut_parameter(_: &mut u32) -> bool { unimplemented!() }
27 /// debug_assert!(take_a_mut_parameter(&mut 5));
29 #[clippy::version = "1.40.0"]
30 pub DEBUG_ASSERT_WITH_MUT_CALL,
32 "mutable arguments in `debug_assert{,_ne,_eq}!`"
35 declare_lint_pass!(DebugAssertWithMutCall => [DEBUG_ASSERT_WITH_MUT_CALL]);
37 const DEBUG_MACRO_NAMES: [&str; 3] = ["debug_assert", "debug_assert_eq", "debug_assert_ne"];
39 impl<'tcx> LateLintPass<'tcx> for DebugAssertWithMutCall {
40 fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
41 for dmn in &DEBUG_MACRO_NAMES {
42 if is_direct_expn_of(e.span, dmn).is_some() {
43 if let Some(macro_args) = higher::extract_assert_macro_args(e) {
44 for arg in macro_args {
45 let mut visitor = MutArgVisitor::new(cx);
46 visitor.visit_expr(arg);
47 if let Some(span) = visitor.expr_span() {
50 DEBUG_ASSERT_WITH_MUT_CALL,
52 &format!("do not call a function with mutable arguments inside of `{}!`", dmn),
62 struct MutArgVisitor<'a, 'tcx> {
63 cx: &'a LateContext<'tcx>,
64 expr_span: Option<Span>,
68 impl<'a, 'tcx> MutArgVisitor<'a, 'tcx> {
69 fn new(cx: &'a LateContext<'tcx>) -> Self {
77 fn expr_span(&self) -> Option<Span> {
78 if self.found { self.expr_span } else { None }
82 impl<'a, 'tcx> Visitor<'tcx> for MutArgVisitor<'a, 'tcx> {
85 fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
87 ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) => {
95 ExprKind::Path(_) => {
96 if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id) {
99 .any(|a| matches!(a.target.kind(), ty::Ref(_, _, Mutability::Mut)))
106 // Don't check await desugars
107 ExprKind::Match(_, _, MatchSource::AwaitDesugar) => return,
108 _ if !self.found => self.expr_span = Some(expr.span),
111 walk_expr(self, expr);
114 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
115 NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())