Auto merge of #4551 - mikerite:fix-ice-reporting, r=llogiq

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

diff --git a/clippy_lints/src/bytecount.rs b/clippy_lints/src/bytecount.rs
index b677ef71583b48fd639a89f11d9604536e3658a3..1e1e4317e34ec48687c4c4da5762cfb453013088 100644 (file)
--- a/clippy_lints/src/bytecount.rs
+++ b/clippy_lints/src/bytecount.rs
@@ -6,59 +6,49 @@
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use rustc::ty;
-use rustc::{declare_tool_lint, lint_array};
+use rustc::{declare_lint_pass, declare_tool_lint};
 use rustc_errors::Applicability;
 use syntax::ast::{Name, UintTy};
 
-/// **What it does:** Checks for naive byte counts
-///
-/// **Why is this bad?** The [`bytecount`](https://crates.io/crates/bytecount)
-/// crate has methods to count your bytes faster, especially for large slices.
-///
-/// **Known problems:** If you have predominantly small slices, the
-/// `bytecount::count(..)` method may actually be slower. However, if you can
-/// ensure that less than 2³²-1 matches arise, the `naive_count_32(..)` can be
-/// faster in those cases.
-///
-/// **Example:**
-///
-/// ```rust
-/// &my_data.filter(|&x| x == 0u8).count() // use bytecount::count instead
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for naive byte counts
+    ///
+    /// **Why is this bad?** The [`bytecount`](https://crates.io/crates/bytecount)
+    /// crate has methods to count your bytes faster, especially for large slices.
+    ///
+    /// **Known problems:** If you have predominantly small slices, the
+    /// `bytecount::count(..)` method may actually be slower. However, if you can
+    /// ensure that less than 2³²-1 matches arise, the `naive_count_32(..)` can be
+    /// faster in those cases.
+    ///
+    /// **Example:**
+    ///
+    /// ```rust
+    /// # let vec = vec![1_u8];
+    /// &vec.iter().filter(|x| **x == 0u8).count(); // use bytecount::count instead
+    /// ```
     pub NAIVE_BYTECOUNT,
     perf,
     "use of naive `<slice>.filter(|&x| x == y).count()` to count byte values"
 }
 
-#[derive(Copy, Clone)]
-pub struct ByteCount;
-
-impl LintPass for ByteCount {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(NAIVE_BYTECOUNT)
-    }
-
-    fn name(&self) -> &'static str {
-        "ByteCount"
-    }
-}
+declare_lint_pass!(ByteCount => [NAIVE_BYTECOUNT]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ByteCount {
     fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr) {
         if_chain! {
             if let ExprKind::MethodCall(ref count, _, ref count_args) = expr.node;
-            if count.ident.name == "count";
+            if count.ident.name == sym!(count);
             if count_args.len() == 1;
             if let ExprKind::MethodCall(ref filter, _, ref filter_args) = count_args[0].node;
-            if filter.ident.name == "filter";
+            if filter.ident.name == sym!(filter);
             if filter_args.len() == 2;
             if let ExprKind::Closure(_, _, body_id, _, _) = filter_args[1].node;
             then {
                 let body = cx.tcx.hir().body(body_id);
                 if_chain! {
-                    if body.arguments.len() == 1;
-                    if let Some(argname) = get_pat_name(&body.arguments[0].pat);
+                    if body.params.len() == 1;
+                    if let Some(argname) = get_pat_name(&body.params[0].pat);
                     if let ExprKind::Binary(ref op, ref l, ref r) = body.value.node;
                     if op.node == BinOpKind::Eq;
                     if match_type(cx,
@@ -78,7 +68,7 @@ fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr) {
                         let haystack = if let ExprKind::MethodCall(ref path, _, ref args) =
                                 filter_args[0].node {
                             let p = path.ident.name;
-                            if (p == "iter" || p == "iter_mut") && args.len() == 1 {
+                            if (p == sym!(iter) || p == sym!(iter_mut)) && args.len() == 1 {
                                 &args[0]
                             } else {
                                 &filter_args[0]
@@ -86,7 +76,7 @@ fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr) {
                         } else {
                             &filter_args[0]
                         };
-                        let mut applicability = Applicability::MachineApplicable;
+                        let mut applicability = Applicability::MaybeIncorrect;
                         span_lint_and_sugg(
                             cx,
                             NAIVE_BYTECOUNT,