Rollup merge of #82917 - cuviper:iter-zip, r=m-ou-se

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

diff --git a/clippy_lints/src/neg_multiply.rs b/clippy_lints/src/neg_multiply.rs
index 55edca6cece26e495842499edf120cc220193cc5..7b00879251f768c4d41b2cab35b4af212812587d 100644 (file)
--- a/clippy_lints/src/neg_multiply.rs
+++ b/clippy_lints/src/neg_multiply.rs
@@ -1,78 +1,53 @@
-// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
+use clippy_utils::diagnostics::span_lint;
 use if_chain::if_chain;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use syntax::source_map::{Span, Spanned};
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
 
 use crate::consts::{self, Constant};
-use crate::utils::span_lint;
 
-/// **What it does:** Checks for multiplication by -1 as a form of negation.
-///
-/// **Why is this bad?** It's more readable to just negate.
-///
-/// **Known problems:** This only catches integers (for now).
-///
-/// **Example:**
-/// ```rust
-/// x * -1
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for multiplication by -1 as a form of negation.
+    ///
+    /// **Why is this bad?** It's more readable to just negate.
+    ///
+    /// **Known problems:** This only catches integers (for now).
+    ///
+    /// **Example:**
+    /// ```ignore
+    /// x * -1
+    /// ```
     pub NEG_MULTIPLY,
     style,
-    "multiplying integers with -1"
+    "multiplying integers with `-1`"
 }
 
-#[derive(Copy, Clone)]
-pub struct NegMultiply;
-
-impl LintPass for NegMultiply {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(NEG_MULTIPLY)
-    }
-}
+declare_lint_pass!(NegMultiply => [NEG_MULTIPLY]);
 
 #[allow(clippy::match_same_arms)]
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NegMultiply {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
-        if let ExprKind::Binary(
-            Spanned {
-                node: BinOpKind::Mul, ..
-            },
-            ref l,
-            ref r,
-        ) = e.node
-        {
-            match (&l.node, &r.node) {
-                (&ExprKind::Unary(..), &ExprKind::Unary(..)) => (),
-                (&ExprKind::Unary(UnNeg, ref lit), _) => check_mul(cx, e.span, lit, r),
-                (_, &ExprKind::Unary(UnNeg, ref lit)) => check_mul(cx, e.span, lit, l),
-                _ => (),
+impl<'tcx> LateLintPass<'tcx> for NegMultiply {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
+        if let ExprKind::Binary(ref op, ref left, ref right) = e.kind {
+            if BinOpKind::Mul == op.node {
+                match (&left.kind, &right.kind) {
+                    (&ExprKind::Unary(..), &ExprKind::Unary(..)) => {},
+                    (&ExprKind::Unary(UnOp::Neg, ref lit), _) => check_mul(cx, e.span, lit, right),
+                    (_, &ExprKind::Unary(UnOp::Neg, ref lit)) => check_mul(cx, e.span, lit, left),
+                    _ => {},
+                }
             }
         }
     }
 }
 
-fn check_mul(cx: &LateContext<'_, '_>, span: Span, lit: &Expr, exp: &Expr) {
+fn check_mul(cx: &LateContext<'_>, span: Span, lit: &Expr<'_>, exp: &Expr<'_>) {
     if_chain! {
-        if let ExprKind::Lit(ref l) = lit.node;
-        if let Constant::Int(val) = consts::lit_to_constant(&l.node, cx.tables.expr_ty(lit));
-        if val == 1;
-        if cx.tables.expr_ty(exp).is_integral();
+        if let ExprKind::Lit(ref l) = lit.kind;
+        if let Constant::Int(1) = consts::lit_to_constant(&l.node, cx.typeck_results().expr_ty_opt(lit));
+        if cx.typeck_results().expr_ty(exp).is_integral();
         then {
-            span_lint(cx,
-                      NEG_MULTIPLY,
-                      span,
-                      "Negation by multiplying with -1");
+            span_lint(cx, NEG_MULTIPLY, span, "negation by multiplying with `-1`");
         }
     }
 }