-use consts::{constant_simple, Constant, FloatWidth};
+use crate::consts::{constant_simple, Constant};
use rustc::lint::*;
+use rustc::{declare_lint, lint_array};
+use if_chain::if_chain;
use rustc::hir::*;
-use utils::span_help_and_lint;
+use crate::utils::span_help_and_lint;
/// **What it does:** Checks for `0.0 / 0.0`.
///
/// ```rust
/// 0.0f32 / 0.0
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub ZERO_DIVIDED_BY_ZERO,
- Warn,
+ complexity,
"usage of `0.0 / 0.0` to obtain NaN instead of std::f32::NaN or std::f64::NaN"
}
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
// check for instances of 0.0/0.0
if_chain! {
- if let ExprBinary(ref op, ref left, ref right) = expr.node;
- if let BinOp_::BiDiv = op.node;
+ if let ExprKind::Binary(ref op, ref left, ref right) = expr.node;
+ 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(Constant::Float(ref lhs_value, lhs_width)) = constant_simple(cx, left);
- if let Some(Constant::Float(ref rhs_value, rhs_width)) = constant_simple(cx, right);
- if Ok(0.0) == lhs_value.parse();
- if Ok(0.0) == rhs_value.parse();
+ if let Some(lhs_value) = constant_simple(cx, cx.tables, left);
+ if let Some(rhs_value) = constant_simple(cx, cx.tables, 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,
// match the precision of the literals that are given.
- let float_type = match (lhs_width, rhs_width) {
- (FloatWidth::F64, _)
- | (_, FloatWidth::F64) => "f64",
+ let float_type = match (lhs_value, rhs_value) {
+ (Constant::F64(_), _)
+ | (_, Constant::F64(_)) => "f64",
_ => "f32"
};
- span_help_and_lint(cx, ZERO_DIVIDED_BY_ZERO, expr.span,
+ span_help_and_lint(
+ cx,
+ ZERO_DIVIDED_BY_ZERO,
+ expr.span,
"constant division of 0.0 with 0.0 will always result in NaN",
- &format!("Consider using `std::{}::NAN` if you would like a constant representing NaN", float_type));
+ &format!(
+ "Consider using `std::{}::NAN` if you would like a constant representing NaN",
+ float_type,
+ ),
+ );
}
}
}