-use crate::consts::{constant_simple, Constant};
-use crate::utils::span_lint_and_help;
+use clippy_utils::consts::{constant_simple, Constant};
+use clippy_utils::diagnostics::span_lint_and_help;
use if_chain::if_chain;
use rustc_hir::{BinOpKind, Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Checks for `0.0 / 0.0`.
+ /// ### What it does
+ /// Checks for `0.0 / 0.0`.
///
- /// **Why is this bad?** It's less readable than `f32::NAN` or `f64::NAN`.
+ /// ### Why is this bad?
+ /// It's less readable than `f32::NAN` or `f64::NAN`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
- /// 0.0f32 / 0.0;
+ /// // Bad
+ /// let nan = 0.0f32 / 0.0;
+ ///
+ /// // Good
+ /// let nan = f32::NAN;
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub ZERO_DIVIDED_BY_ZERO,
complexity,
"usage of `0.0 / 0.0` to obtain NaN instead of `f32::NAN` or `f64::NAN`"
declare_lint_pass!(ZeroDiv => [ZERO_DIVIDED_BY_ZERO]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ZeroDiv {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for ZeroDiv {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
// check for instances of 0.0/0.0
if_chain! {
- if let ExprKind::Binary(ref op, ref left, ref right) = expr.kind;
- if let BinOpKind::Div = op.node;
+ if let ExprKind::Binary(ref op, left, right) = expr.kind;
+ if op.node == BinOpKind::Div;
// TODO - constant_simple does not fold many operations involving floats.
// That's probably fine for this lint - it's pretty unlikely that someone would
// do something like 0.0/(2.0 - 2.0), but it would be nice to warn on that case too.
- if let Some(lhs_value) = constant_simple(cx, cx.tables, left);
- if let Some(rhs_value) = constant_simple(cx, cx.tables, right);
+ if let Some(lhs_value) = constant_simple(cx, cx.typeck_results(), left);
+ if let Some(rhs_value) = constant_simple(cx, cx.typeck_results(), right);
if Constant::F32(0.0) == lhs_value || Constant::F64(0.0) == lhs_value;
if Constant::F32(0.0) == rhs_value || Constant::F64(0.0) == rhs_value;
then {
ZERO_DIVIDED_BY_ZERO,
expr.span,
"constant division of `0.0` with `0.0` will always result in NaN",
+ None,
&format!(
- "Consider using `{}::NAN` if you would like a constant representing NaN",
+ "consider using `{}::NAN` if you would like a constant representing NaN",
float_type,
),
);