X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fminmax.rs;h=749f6b9251512cb8b2810edf361d4217b75f5cfb;hb=5ac08b0cc94cab09fba719a17c141c68c4cbc063;hp=4be2b9f522711a11f53c8dcb5e855d1e4979dc83;hpb=73a80c5950b1d6ac6f3479913c4e5f9d0f0455b1;p=rust.git

diff --git a/clippy_lints/src/minmax.rs b/clippy_lints/src/minmax.rs
index 4be2b9f5227..749f6b92515 100644
--- a/clippy_lints/src/minmax.rs
+++ b/clippy_lints/src/minmax.rs
@@ -1,40 +1,35 @@
 use crate::consts::{constant_simple, Constant};
-use crate::utils::{match_def_path, opt_def_id, paths, span_lint};
-use rustc::hir::*;
-use rustc::lint::*;
+use crate::utils::{match_def_path, paths, span_lint};
+use rustc::declare_lint_pass;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc_hir::*;
+use rustc_session::declare_tool_lint;
 use std::cmp::Ordering;
 
-/// **What it does:** Checks for expressions where `std::cmp::min` and `max` are
-/// used to clamp values, but switched so that the result is constant.
-///
-/// **Why is this bad?** This is in all probability not the intended outcome. At
-/// the least it hurts readability of the code.
-///
-/// **Known problems:** None
-///
-/// **Example:**
-/// ```rust
-/// min(0, max(100, x))
-/// ```
-/// It will always be equal to `0`. Probably the author meant to clamp the value
-/// between 0 and 100, but has erroneously swapped `min` and `max`.
 declare_clippy_lint! {
+    /// **What it does:** Checks for expressions where `std::cmp::min` and `max` are
+    /// used to clamp values, but switched so that the result is constant.
+    ///
+    /// **Why is this bad?** This is in all probability not the intended outcome. At
+    /// the least it hurts readability of the code.
+    ///
+    /// **Known problems:** None
+    ///
+    /// **Example:**
+    /// ```ignore
+    /// min(0, max(100, x))
+    /// ```
+    /// It will always be equal to `0`. Probably the author meant to clamp the value
+    /// between 0 and 100, but has erroneously swapped `min` and `max`.
     pub MIN_MAX,
     correctness,
     "`min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant"
 }
 
-#[allow(missing_copy_implementations)]
-pub struct MinMaxPass;
-
-impl LintPass for MinMaxPass {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(MIN_MAX)
-    }
-}
+declare_lint_pass!(MinMaxPass => [MIN_MAX]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MinMaxPass {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
         if let Some((outer_max, outer_c, oe)) = min_max(cx, expr) {
             if let Some((inner_max, inner_c, ie)) = min_max(cx, oe) {
                 if outer_max == inner_max {
@@ -42,7 +37,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
                 }
                 match (
                     outer_max,
-                    Constant::partial_cmp(cx.tcx, &cx.tables.expr_ty(ie).sty, &outer_c, &inner_c),
+                    Constant::partial_cmp(cx.tcx, cx.tables.expr_ty(ie), &outer_c, &inner_c),
                 ) {
                     (_, None) | (MinMax::Max, Some(Ordering::Less)) | (MinMax::Min, Some(Ordering::Greater)) => (),
                     _ => {
@@ -50,7 +45,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
                             cx,
                             MIN_MAX,
                             expr.span,
-                            "this min/max combination leads to constant result",
+                            "this `min`/`max` combination leads to constant result",
                         );
                     },
                 }
@@ -65,13 +60,13 @@ enum MinMax {
     Max,
 }
 
-fn min_max<'a>(cx: &LateContext, expr: &'a Expr) -> Option<(MinMax, Constant, &'a Expr)> {
-    if let ExprCall(ref path, ref args) = expr.node {
-        if let ExprPath(ref qpath) = path.node {
-            opt_def_id(cx.tables.qpath_def(qpath, path.hir_id)).and_then(|def_id| {
-                if match_def_path(cx.tcx, def_id, &paths::CMP_MIN) {
+fn min_max<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'a>) -> Option<(MinMax, Constant, &'a Expr<'a>)> {
+    if let ExprKind::Call(ref path, ref args) = expr.kind {
+        if let ExprKind::Path(ref qpath) = path.kind {
+            cx.tables.qpath_res(qpath, path.hir_id).opt_def_id().and_then(|def_id| {
+                if match_def_path(cx, def_id, &paths::CMP_MIN) {
                     fetch_const(cx, args, MinMax::Min)
-                } else if match_def_path(cx.tcx, def_id, &paths::CMP_MAX) {
+                } else if match_def_path(cx, def_id, &paths::CMP_MAX) {
                     fetch_const(cx, args, MinMax::Max)
                 } else {
                     None
@@ -85,7 +80,11 @@ fn min_max<'a>(cx: &LateContext, expr: &'a Expr) -> Option<(MinMax, Constant, &'
     }
 }
 
-fn fetch_const<'a>(cx: &LateContext, args: &'a [Expr], m: MinMax) -> Option<(MinMax, Constant, &'a Expr)> {
+fn fetch_const<'a>(
+    cx: &LateContext<'_, '_>,
+    args: &'a [Expr<'a>],
+    m: MinMax,
+) -> Option<(MinMax, Constant, &'a Expr<'a>)> {
     if args.len() != 2 {
         return None;
     }