use crate::consts::{constant_simple, Constant};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::utils::span_lint_and_help;
use if_chain::if_chain;
-use rustc::hir::*;
-use crate::utils::span_help_and_lint;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
-/// **What it does:** Checks for `0.0 / 0.0`.
-///
-/// **Why is this bad?** It's less readable than `std::f32::NAN` or
-/// `std::f64::NAN`.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// 0.0f32 / 0.0
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `0.0 / 0.0`.
+ ///
+ /// **Why is this bad?** It's less readable than `f32::NAN` or `f64::NAN`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Bad
+ /// let nan = 0.0f32 / 0.0;
+ ///
+ /// // Good
+ /// let nan = f32::NAN;
+ /// ```
pub ZERO_DIVIDED_BY_ZERO,
complexity,
- "usage of `0.0 / 0.0` to obtain NaN instead of std::f32::NaN or std::f64::NaN"
+ "usage of `0.0 / 0.0` to obtain NaN instead of `f32::NAN` or `f64::NAN`"
}
-pub struct Pass;
+declare_lint_pass!(ZeroDiv => [ZERO_DIVIDED_BY_ZERO]);
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(ZERO_DIVIDED_BY_ZERO)
- }
-}
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- 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.node;
+ if let ExprKind::Binary(ref op, ref left, ref right) = expr.kind;
if let BinOpKind::Div = op.node;
// 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 {
- // since we're about to suggest a use of std::f32::NaN or std::f64::NaN,
+ // since we're about to suggest a use of f32::NAN or f64::NAN,
// match the precision of the literals that are given.
let float_type = match (lhs_value, rhs_value) {
(Constant::F64(_), _)
| (_, Constant::F64(_)) => "f64",
_ => "f32"
};
- span_help_and_lint(
+ span_lint_and_help(
cx,
ZERO_DIVIDED_BY_ZERO,
expr.span,
- "constant division of 0.0 with 0.0 will always result in NaN",
+ "constant division of `0.0` with `0.0` will always result in NaN",
+ None,
&format!(
- "Consider using `std::{}::NAN` if you would like a constant representing NaN",
+ "consider using `{}::NAN` if you would like a constant representing NaN",
float_type,
),
);