use crate::consts::constant_simple;
use crate::utils::span_lint;
-use rustc::hir;
-use rustc::impl_lint_pass;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc_session::declare_tool_lint;
-use syntax::source_map::Span;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
declare_clippy_lint! {
- /// **What it does:** Checks for plain integer arithmetic.
+ /// **What it does:** Checks for integer arithmetic operations which could overflow or panic.
///
- /// **Why is this bad?** This is only checked against overflow in debug builds.
- /// In some applications one wants explicitly checked, wrapping or saturating
- /// arithmetic.
+ /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
+ /// of overflowing according to the [Rust
+ /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
+ /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
+ /// attempted.
+ ///
+ /// **Why is this bad?** Integer overflow will trigger a panic in debug builds or will wrap in
+ /// release mode. Division by zero will cause a panic in either mode. In some applications one
+ /// wants explicitly checked, wrapping or saturating arithmetic.
///
/// **Known problems:** None.
///
/// ```
pub INTEGER_ARITHMETIC,
restriction,
- "any integer arithmetic statement"
+ "any integer arithmetic expression which could overflow or panic"
}
declare_clippy_lint! {
impl_lint_pass!(Arithmetic => [INTEGER_ARITHMETIC, FLOAT_ARITHMETIC]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Arithmetic {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
+impl<'tcx> LateLintPass<'tcx> for Arithmetic {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
if self.expr_span.is_some() {
return;
}
| hir::BinOpKind::BitAnd
| hir::BinOpKind::BitOr
| hir::BinOpKind::BitXor
- | hir::BinOpKind::Shl
- | hir::BinOpKind::Shr
| hir::BinOpKind::Eq
| hir::BinOpKind::Lt
| hir::BinOpKind::Le
| hir::BinOpKind::Gt => return,
_ => (),
}
- let (l_ty, r_ty) = (cx.tables.expr_ty(l), cx.tables.expr_ty(r));
- if l_ty.is_integral() && r_ty.is_integral() {
- span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
- self.expr_span = Some(expr.span);
- } else if l_ty.is_floating_point() && r_ty.is_floating_point() {
+
+ let (l_ty, r_ty) = (cx.typeck_results().expr_ty(l), cx.typeck_results().expr_ty(r));
+ if l_ty.peel_refs().is_integral() && r_ty.peel_refs().is_integral() {
+ match op.node {
+ hir::BinOpKind::Div | hir::BinOpKind::Rem => match &r.kind {
+ hir::ExprKind::Lit(_lit) => (),
+ hir::ExprKind::Unary(hir::UnOp::UnNeg, expr) => {
+ if let hir::ExprKind::Lit(lit) = &expr.kind {
+ if let rustc_ast::ast::LitKind::Int(1, _) = lit.node {
+ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
+ self.expr_span = Some(expr.span);
+ }
+ }
+ },
+ _ => {
+ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
+ self.expr_span = Some(expr.span);
+ },
+ },
+ _ => {
+ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
+ self.expr_span = Some(expr.span);
+ },
+ }
+ } else if r_ty.peel_refs().is_floating_point() && r_ty.peel_refs().is_floating_point() {
span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
self.expr_span = Some(expr.span);
}
},
hir::ExprKind::Unary(hir::UnOp::UnNeg, arg) => {
- let ty = cx.tables.expr_ty(arg);
- if constant_simple(cx, cx.tables, expr).is_none() {
+ let ty = cx.typeck_results().expr_ty(arg);
+ if constant_simple(cx, cx.typeck_results(), expr).is_none() {
if ty.is_integral() {
span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
self.expr_span = Some(expr.span);
}
}
- fn check_expr_post(&mut self, _: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
+ fn check_expr_post(&mut self, _: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
if Some(expr.span) == self.expr_span {
self.expr_span = None;
}
}
- fn check_body(&mut self, cx: &LateContext<'_, '_>, body: &hir::Body) {
+ fn check_body(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
let body_owner = cx.tcx.hir().body_owner(body.id());
match cx.tcx.hir().body_owner_kind(body_owner) {
}
}
- fn check_body_post(&mut self, cx: &LateContext<'_, '_>, body: &hir::Body) {
+ fn check_body_post(&mut self, cx: &LateContext<'_>, body: &hir::Body<'_>) {
let body_owner = cx.tcx.hir().body_owner(body.id());
let body_span = cx.tcx.hir().span(body_owner);