Auto merge of #5334 - flip1995:backport_remerge, r=flip1995

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

diff --git a/clippy_lints/src/ranges.rs b/clippy_lints/src/ranges.rs
index 6a16adf71dc173fd1a72a6d5e8e8cc7c03d61a95..c9de88d9c83d2e157d059a7cc9281bd6322afb12 100644 (file)
--- a/clippy_lints/src/ranges.rs
+++ b/clippy_lints/src/ranges.rs
@@ -1,11 +1,10 @@
 use if_chain::if_chain;
-use rustc::declare_lint_pass;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc_ast::ast::RangeLimits;
 use rustc_errors::Applicability;
-use rustc_session::declare_tool_lint;
-use syntax::ast::RangeLimits;
-use syntax::source_map::Spanned;
+use rustc_hir::{BinOpKind, Expr, ExprKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
 
 use crate::utils::sugg::Sugg;
 use crate::utils::{higher, SpanlessEq};
@@ -46,6 +45,10 @@
     /// and ends with a closing one.
     /// I.e., `let _ = (f()+1)..(f()+1)` results in `let _ = ((f()+1)..=f())`.
     ///
+    /// Also in many cases, inclusive ranges are still slower to run than
+    /// exclusive ranges, because they essentially add an extra branch that
+    /// LLVM may fail to hoist out of the loop.
+    ///
     /// **Example:**
     /// ```rust,ignore
     /// for x..(y+1) { .. }
@@ -55,7 +58,7 @@
     /// for x..=y { .. }
     /// ```
     pub RANGE_PLUS_ONE,
-    complexity,
+    pedantic,
     "`x..(y+1)` reads better as `x..=y`"
 }
 
@@ -88,7 +91,7 @@
 ]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Ranges {
-    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 ExprKind::MethodCall(ref path, _, ref args) = expr.kind {
             let name = path.ident.as_str();
             if name == "zip" && args.len() == 2 {
@@ -112,7 +115,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
                          span_lint(cx,
                                    RANGE_ZIP_WITH_LEN,
                                    expr.span,
-                                   &format!("It is more idiomatic to use {}.iter().enumerate()",
+                                   &format!("It is more idiomatic to use `{}.iter().enumerate()`",
                                             snippet(cx, iter_args[0].span, "_")));
                     }
                 }
@@ -125,7 +128,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
 }
 
 // exclusive range plus one: `x..(y+1)`
-fn check_exclusive_range_plus_one(cx: &LateContext<'_, '_>, expr: &Expr) {
+fn check_exclusive_range_plus_one(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
     if_chain! {
         if let Some(higher::Range {
             start,
@@ -174,7 +177,7 @@ fn check_exclusive_range_plus_one(cx: &LateContext<'_, '_>, expr: &Expr) {
 }
 
 // inclusive range minus one: `x..=(y-1)`
-fn check_inclusive_range_minus_one(cx: &LateContext<'_, '_>, expr: &Expr) {
+fn check_inclusive_range_minus_one(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
     if_chain! {
         if let Some(higher::Range { start, end: Some(end), limits: RangeLimits::Closed }) = higher::range(cx, expr);
         if let Some(y) = y_minus_one(cx, end);
@@ -199,7 +202,7 @@ fn check_inclusive_range_minus_one(cx: &LateContext<'_, '_>, expr: &Expr) {
     }
 }
 
-fn y_plus_one<'t>(cx: &LateContext<'_, '_>, expr: &'t Expr) -> Option<&'t Expr> {
+fn y_plus_one<'t>(cx: &LateContext<'_, '_>, expr: &'t Expr<'_>) -> Option<&'t Expr<'t>> {
     match expr.kind {
         ExprKind::Binary(
             Spanned {
@@ -220,7 +223,7 @@ fn y_plus_one<'t>(cx: &LateContext<'_, '_>, expr: &'t Expr) -> Option<&'t Expr>
     }
 }
 
-fn y_minus_one<'t>(cx: &LateContext<'_, '_>, expr: &'t Expr) -> Option<&'t Expr> {
+fn y_minus_one<'t>(cx: &LateContext<'_, '_>, expr: &'t Expr<'_>) -> Option<&'t Expr<'t>> {
     match expr.kind {
         ExprKind::Binary(
             Spanned {