3 use syntax::codemap::Span;
4 use crate::utils::span_lint;
6 /// **What it does:** Checks for plain integer arithmetic.
8 /// **Why is this bad?** This is only checked against overflow in debug builds.
9 /// In some applications one wants explicitly checked, wrapping or saturating
12 /// **Known problems:** None.
18 declare_clippy_lint! {
19 pub INTEGER_ARITHMETIC,
21 "any integer arithmetic statement"
24 /// **What it does:** Checks for float arithmetic.
26 /// **Why is this bad?** For some embedded systems or kernel development, it
27 /// can be useful to rule out floating-point numbers.
29 /// **Known problems:** None.
35 declare_clippy_lint! {
38 "any floating-point arithmetic statement"
41 #[derive(Copy, Clone, Default)]
42 pub struct Arithmetic {
46 impl LintPass for Arithmetic {
47 fn get_lints(&self) -> LintArray {
48 lint_array!(INTEGER_ARITHMETIC, FLOAT_ARITHMETIC)
52 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Arithmetic {
53 fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
54 if self.span.is_some() {
58 hir::ExprBinary(ref op, ref l, ref r) => {
72 | hir::BiGt => return,
75 let (l_ty, r_ty) = (cx.tables.expr_ty(l), cx.tables.expr_ty(r));
76 if l_ty.is_integral() && r_ty.is_integral() {
77 span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
78 self.span = Some(expr.span);
79 } else if l_ty.is_floating_point() && r_ty.is_floating_point() {
80 span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
81 self.span = Some(expr.span);
84 hir::ExprUnary(hir::UnOp::UnNeg, ref arg) => {
85 let ty = cx.tables.expr_ty(arg);
87 span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
88 self.span = Some(expr.span);
89 } else if ty.is_floating_point() {
90 span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
91 self.span = Some(expr.span);
98 fn check_expr_post(&mut self, _: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
99 if Some(expr.span) == self.span {