+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::implements_trait;
+use clippy_utils::{self, get_trait_def_id, paths};
use if_chain::if_chain;
-use rustc::hir::*;
-use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
-
-use crate::utils::{self, paths, span_lint};
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:**
+ /// ### What it does
/// Checks for the usage of negated comparison operators on types which only implement
/// `PartialOrd` (e.g., `f64`).
///
- /// **Why is this bad?**
+ /// ### 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:**
- ///
+ /// ### Example
/// ```rust
- /// use std::cmp::Ordering;
- ///
- /// // Bad
/// let a = 1.0;
- /// let b = std::f64::NAN;
+ /// let b = f64::NAN;
///
- /// let _not_less_or_equal = !(a <= b);
+ /// let not_less_or_equal = !(a <= b);
+ /// ```
///
- /// // Good
- /// let a = 1.0;
- /// let b = std::f64::NAN;
+ /// Use instead:
+ /// ```rust
+ /// use std::cmp::Ordering;
+ /// # let a = 1.0;
+ /// # let b = f64::NAN;
///
/// let _not_less_or_equal = match a.partial_cmp(&b) {
/// None | Some(Ordering::Greater) => true,
/// _ => false,
/// };
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub NEG_CMP_OP_ON_PARTIAL_ORD,
complexity,
"The use of negated comparison operators on partially ordered types may produce confusing code."
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) {
+impl<'tcx> LateLintPass<'tcx> for NoNegCompOpForPartialOrd {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
if !in_external_macro(cx.sess(), expr.span);
- if let ExprKind::Unary(UnOp::UnNot, ref inner) = expr.node;
- if let ExprKind::Binary(ref op, ref left, _) = inner.node;
+ if let ExprKind::Unary(UnOp::Not, inner) = expr.kind;
+ if let ExprKind::Binary(ref op, left, _) = inner.kind;
if let BinOpKind::Le | BinOpKind::Ge | BinOpKind::Lt | BinOpKind::Gt = op.node;
then {
- let ty = cx.tables.expr_ty(left);
+ let ty = cx.typeck_results().expr_ty(left);
let implements_ord = {
- if let Some(id) = utils::get_trait_def_id(cx, &paths::ORD) {
- utils::implements_trait(cx, ty, id, &[])
+ if let Some(id) = get_trait_def_id(cx, &paths::ORD) {
+ implements_trait(cx, ty, id, &[])
} else {
return;
}
};
let implements_partial_ord = {
- if let Some(id) = utils::get_trait_def_id(cx, &paths::PARTIAL_ORD) {
- utils::implements_trait(cx, ty, id, &[])
+ if let Some(id) = cx.tcx.lang_items().partial_ord_trait() {
+ implements_trait(cx, ty, id, &[])
} else {
return;
}
cx,
NEG_CMP_OP_ON_PARTIAL_ORD,
expr.span,
- "The use of negated comparison operators on partially ordered \
- types produces code that is hard to read and refactor. Please \
+ "the use of negated comparison operators on partially ordered \
+ types produces code that is hard to read and refactor, please \
consider using the `partial_cmp` method instead, to make it \
- clear that the two values could be incomparable."
- )
+ clear that the two values could be incomparable"
+ );
}
}
}