+use if_chain::if_chain;
+use rustc::declare_lint_pass;
use rustc::hir::*;
-use rustc::lint::*;
+use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
+use rustc_session::declare_tool_lint;
-use crate::utils::{self, paths};
+use crate::utils::{self, paths, span_lint};
-/// **What it does:**
-/// Checks for the usage of negated comparision operators on types which only implement
-/// `PartialOrd` (e.g. `f64`).
-///
-/// **Why is this bad?**
-/// These operators make it easy to forget that the underlying types actually allow not only three
-/// potential Orderings (Less, Equal, Greater) but also a forth one (Uncomparable). Escpeccially if
-/// the operator based comparision result is negated it is easy to miss that fact.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-///
-/// ```rust
-/// use core::cmp::Ordering;
-///
-/// // Bad
-/// let a = 1.0;
-/// let b = std::f64::NAN;
-///
-/// let _not_less_or_equal = !(a <= b);
-///
-/// // Good
-/// let a = 1.0;
-/// let b = std::f64::NAN;
-///
-/// let _not_less_or_equal = match a.partial_cmp(&b) {
-/// None | Some(Ordering::Greater) => true,
-/// _ => false,
-/// };
-/// ```
declare_clippy_lint! {
+ /// **What it does:**
+ /// Checks for the usage of negated comparison operators on types which only implement
+ /// `PartialOrd` (e.g., `f64`).
+ ///
+ /// **Why is this bad?**
+ /// These operators make it easy to forget that the underlying types actually allow not only three
+ /// potential Orderings (Less, Equal, Greater) but also a fourth one (Uncomparable). This is
+ /// especially easy to miss if the operator based comparison result is negated.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// use std::cmp::Ordering;
+ ///
+ /// // Bad
+ /// let a = 1.0;
+ /// let b = std::f64::NAN;
+ ///
+ /// let _not_less_or_equal = !(a <= b);
+ ///
+ /// // Good
+ /// let a = 1.0;
+ /// let b = std::f64::NAN;
+ ///
+ /// let _not_less_or_equal = match a.partial_cmp(&b) {
+ /// None | Some(Ordering::Greater) => true,
+ /// _ => false,
+ /// };
+ /// ```
pub NEG_CMP_OP_ON_PARTIAL_ORD,
complexity,
- "The use of negated comparision operators on partially orded types may produce confusing code."
+ "The use of negated comparison operators on partially ordered types may produce confusing code."
}
-pub struct NoNegCompOpForPartialOrd;
-
-impl LintPass for NoNegCompOpForPartialOrd {
- fn get_lints(&self) -> LintArray {
- lint_array!(NEG_CMP_OP_ON_PARTIAL_ORD)
- }
-}
+declare_lint_pass!(NoNegCompOpForPartialOrd => [NEG_CMP_OP_ON_PARTIAL_ORD]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NoNegCompOpForPartialOrd {
-
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
if_chain! {
- if let Expr_::ExprUnary(UnOp::UnNot, ref inner) = expr.node;
- if let Expr_::ExprBinary(ref op, ref left, _) = inner.node;
- if let BinOp_::BiLe | BinOp_::BiGe | BinOp_::BiLt | BinOp_::BiGt = op.node;
+ if !in_external_macro(cx.sess(), expr.span);
+ if let ExprKind::Unary(UnOp::UnNot, ref inner) = expr.kind;
+ if let ExprKind::Binary(ref op, ref left, _) = inner.kind;
+ if let BinOpKind::Le | BinOpKind::Ge | BinOpKind::Lt | BinOpKind::Gt = op.node;
then {
};
if implements_partial_ord && !implements_ord {
- cx.span_lint(
+ span_lint(
+ cx,
NEG_CMP_OP_ON_PARTIAL_ORD,
expr.span,
- "The use of negated comparision operators on partially orded \
+ "The use of negated comparison operators on partially ordered \
types produces code that is hard to read and refactor. Please \
- consider to use the `partial_cmp` instead, to make it clear \
- that the two values could be incomparable."
+ consider using the `partial_cmp` method instead, to make it \
+ clear that the two values could be incomparable."
)
}
}