Auto merge of #4809 - iankronquist:patch-1, r=flip1995

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

diff --git a/clippy_lints/src/large_enum_variant.rs b/clippy_lints/src/large_enum_variant.rs
index a6d34f2c7a234290b500d5098826d18bb985e8b3..0cd02f21238d22d896786296acd105dce8a71964 100644 (file)
--- a/clippy_lints/src/large_enum_variant.rs
+++ b/clippy_lints/src/large_enum_variant.rs
@@ -1,29 +1,29 @@
 //! lint when there is a large size difference between variants on an enum
 
 use crate::utils::{snippet_opt, span_lint_and_then};
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use rustc::ty::layout::LayoutOf;
-use rustc::{declare_tool_lint, lint_array};
 use rustc_errors::Applicability;
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 
-/// **What it does:** Checks for large size differences between variants on
-/// `enum`s.
-///
-/// **Why is this bad?** Enum size is bounded by the largest variant. Having a
-/// large variant
-/// can penalize the memory layout of that enum.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// enum Test {
-///     A(i32),
-///     B([i32; 8000]),
-/// }
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for large size differences between variants on
+    /// `enum`s.
+    ///
+    /// **Why is this bad?** Enum size is bounded by the largest variant. Having a
+    /// large variant
+    /// can penalize the memory layout of that enum.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// enum Test {
+    ///     A(i32),
+    ///     B([i32; 8000]),
+    /// }
+    /// ```
     pub LARGE_ENUM_VARIANT,
     perf,
     "large size difference between variants on an enum"
@@ -35,6 +35,7 @@ pub struct LargeEnumVariant {
 }
 
 impl LargeEnumVariant {
+    #[must_use]
     pub fn new(maximum_size_difference_allowed: u64) -> Self {
         Self {
             maximum_size_difference_allowed,
@@ -42,20 +43,12 @@ pub fn new(maximum_size_difference_allowed: u64) -> Self {
     }
 }
 
-impl LintPass for LargeEnumVariant {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(LARGE_ENUM_VARIANT)
-    }
-
-    fn name(&self) -> &'static str {
-        "LargeEnumVariant"
-    }
-}
+impl_lint_pass!(LargeEnumVariant => [LARGE_ENUM_VARIANT]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeEnumVariant {
-    fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item) {
-        let did = cx.tcx.hir().local_def_id(item.id);
-        if let ItemKind::Enum(ref def, _) = item.node {
+    fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item<'_>) {
+        let did = cx.tcx.hir().local_def_id(item.hir_id);
+        if let ItemKind::Enum(ref def, _) = item.kind {
             let ty = cx.tcx.type_of(did);
             let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
 
@@ -93,7 +86,7 @@ fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item) {
                         "large size difference between variants",
                         |db| {
                             if variant.fields.len() == 1 {
-                                let span = match def.variants[i].node.data {
+                                let span = match def.variants[i].data {
                                     VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, ..) => {
                                         fields[0].ty.span
                                     },