3 use syntax::codemap::Span;
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_restriction_lint! {
19 pub INTEGER_ARITHMETIC,
20 "any integer arithmetic statement"
23 /// **What it does:** Checks for float arithmetic.
25 /// **Why is this bad?** For some embedded systems or kernel development, it
26 /// can be useful to rule out floating-point numbers.
28 /// **Known problems:** None.
34 declare_restriction_lint! {
36 "any floating-point arithmetic statement"
39 #[derive(Copy, Clone, Default)]
40 pub struct Arithmetic {
44 impl LintPass for Arithmetic {
45 fn get_lints(&self) -> LintArray {
46 lint_array!(INTEGER_ARITHMETIC, FLOAT_ARITHMETIC)
50 impl LateLintPass for Arithmetic {
51 fn check_expr(&mut self, cx: &LateContext, expr: &hir::Expr) {
52 if let Some(_) = self.span {
56 hir::ExprBinary(ref op, ref l, ref r) => {
58 hir::BiAnd | hir::BiOr | hir::BiBitAnd | hir::BiBitOr | hir::BiBitXor | hir::BiShl |
59 hir::BiShr | hir::BiEq | hir::BiLt | hir::BiLe | hir::BiNe | hir::BiGe | hir::BiGt => return,
62 let (l_ty, r_ty) = (cx.tcx.expr_ty(l), cx.tcx.expr_ty(r));
63 if l_ty.is_integral() && r_ty.is_integral() {
64 span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
65 self.span = Some(expr.span);
66 } else if l_ty.is_floating_point() && r_ty.is_floating_point() {
67 span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
68 self.span = Some(expr.span);
71 hir::ExprUnary(hir::UnOp::UnNeg, ref arg) => {
72 let ty = cx.tcx.expr_ty(arg);
74 span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
75 self.span = Some(expr.span);
76 } else if ty.is_floating_point() {
77 span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
78 self.span = Some(expr.span);
85 fn check_expr_post(&mut self, _: &LateContext, expr: &hir::Expr) {
86 if Some(expr.span) == self.span {