-// 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.
-
-
//! Lint on unnecessary double comparisons. Some examples:
-use crate::rustc::hir::*;
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::syntax::source_map::Span;
+use rustc::hir::*;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_errors::Applicability;
+use syntax::source_map::Span;
-use crate::utils::{snippet, span_lint_and_sugg, SpanlessEq};
+use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
-/// **What it does:** Checks for double comparions that could be simpified to a single expression.
-///
-///
-/// **Why is this bad?** Readability.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// x == y || x < y
-/// ```
-///
-/// Could be written as:
-///
-/// ```rust
-/// x <= y
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for double comparions that could be simplified to a single expression.
+ ///
+ ///
+ /// **Why is this bad?** Readability.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// x == y || x < y
+ /// ```
+ ///
+ /// Could be written as:
+ ///
+ /// ```rust
+ /// x <= y
+ /// ```
pub DOUBLE_COMPARISONS,
complexity,
"unnecessary double comparisons that can be simplified"
}
-pub struct DoubleComparisonPass;
+pub struct Pass;
-impl LintPass for DoubleComparisonPass {
+impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
lint_array!(DOUBLE_COMPARISONS)
}
+
+ fn name(&self) -> &'static str {
+ "DoubleComparisons"
+ }
}
-impl<'a, 'tcx> DoubleComparisonPass {
- fn check_binop(
- &self,
- cx: &LateContext<'a, 'tcx>,
- op: BinOpKind,
- lhs: &'tcx Expr,
- rhs: &'tcx Expr,
- span: Span,
- ) {
+impl<'a, 'tcx> Pass {
+ #[allow(clippy::similar_names)]
+ fn check_binop(&self, cx: &LateContext<'a, 'tcx>, op: BinOpKind, lhs: &'tcx Expr, rhs: &'tcx Expr, span: Span) {
let (lkind, llhs, lrhs, rkind, rlhs, rrhs) = match (lhs.node.clone(), rhs.node.clone()) {
(ExprKind::Binary(lb, llhs, lrhs), ExprKind::Binary(rb, rlhs, rrhs)) => {
(lb.node, llhs, lrhs, rb.node, rlhs, rrhs)
- }
+ },
_ => return,
};
let mut spanless_eq = SpanlessEq::new(cx).ignore_fn();
}
macro_rules! lint_double_comparison {
($op:tt) => {{
- let lhs_str = snippet(cx, llhs.span, "");
- let rhs_str = snippet(cx, lrhs.span, "");
+ let mut applicability = Applicability::MachineApplicable;
+ let lhs_str = snippet_with_applicability(cx, llhs.span, "", &mut applicability);
+ let rhs_str = snippet_with_applicability(cx, lrhs.span, "", &mut applicability);
let sugg = format!("{} {} {}", lhs_str, stringify!($op), rhs_str);
- span_lint_and_sugg(cx, DOUBLE_COMPARISONS, span,
- "This binary expression can be simplified",
- "try", sugg);
- }}
+ span_lint_and_sugg(
+ cx,
+ DOUBLE_COMPARISONS,
+ span,
+ "This binary expression can be simplified",
+ "try",
+ sugg,
+ applicability,
+ );
+ }};
}
match (op, lkind, rkind) {
- (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Lt) | (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Eq) => lint_double_comparison!(<=),
- (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Eq) => lint_double_comparison!(>=),
- (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Lt) => lint_double_comparison!(!=),
- (BinOpKind::And, BinOpKind::Le, BinOpKind::Ge) | (BinOpKind::And, BinOpKind::Ge, BinOpKind::Le) => lint_double_comparison!(==),
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Lt) | (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Eq) => {
+ lint_double_comparison!(<=)
+ },
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Eq) => {
+ lint_double_comparison!(>=)
+ },
+ (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Lt) => {
+ lint_double_comparison!(!=)
+ },
+ (BinOpKind::And, BinOpKind::Le, BinOpKind::Ge) | (BinOpKind::And, BinOpKind::Ge, BinOpKind::Le) => {
+ lint_double_comparison!(==)
+ },
_ => (),
};
}
}
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DoubleComparisonPass {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = expr.node {
self.check_binop(cx, kind.node, lhs, rhs, expr.span);