Shrink `hir::def::Res`.

[rust.git] / clippy_lints / src / neg_cmp_op_on_partial_ord.rs

diff --git a/clippy_lints/src/neg_cmp_op_on_partial_ord.rs b/clippy_lints/src/neg_cmp_op_on_partial_ord.rs
index 50031dd68cf15dd2e5496e3f1d9bb91c22c31458..a7e0e35787cffbcc092d5ae27a293bbac7a60244 100644 (file)
--- a/clippy_lints/src/neg_cmp_op_on_partial_ord.rs
+++ b/clippy_lints/src/neg_cmp_op_on_partial_ord.rs
@@ -1,83 +1,73 @@
+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_tool_lint, lint_array};
+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};
 
-use crate::utils::{self, paths, span_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,
-/// };
-/// ```
 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.
+    ///
+    /// ### Example
+    /// ```rust
+    /// let a = 1.0;
+    /// let b = f64::NAN;
+    ///
+    /// let not_less_or_equal = !(a <= b);
+    /// ```
+    ///
+    /// 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."
 }
 
-pub struct NoNegCompOpForPartialOrd;
-
-impl LintPass for NoNegCompOpForPartialOrd {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(NEG_CMP_OP_ON_PARTIAL_ORD)
-    }
-
-    fn name(&self) -> &'static str {
-        "NoNegCompOpForPartialOrd"
-    }
-}
+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;
                     }
@@ -88,11 +78,11 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
                         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"
+                    );
                 }
             }
         }