Make exhaustive_enums only warn on exported items

clippy_lints/src/exhaustive_enums.rs

@@ -7,7 +7,7 @@
 use rustc_span::sym;
 
 declare_clippy_lint! {
-    /// **What it does:** Warns on any `enum`s that are not tagged `#[non_exhaustive]`
+    /// **What it does:** Warns on any exported `enum`s that are not tagged `#[non_exhaustive]`
     ///
     /// **Why is this bad?** Exhaustive enums are typically fine, but a project which does
     /// not wish to make a stability commitment around enums may wish to disable them by default.
@@ -40,6 +40,7 @@ impl LateLintPass<'_> for ExhaustiveEnums {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         if_chain! {
             if let ItemKind::Enum(..) = item.kind;
+            if cx.access_levels.is_exported(item.hir_id);
             if !item.attrs.iter().any(|a| a.has_name(sym::non_exhaustive));
             then {
                 if let Some(snippet) = snippet_opt(cx, item.span) {

tests/ui/exhaustive_enums.fixed

@@ -8,15 +8,33 @@ fn main() {
 }
 
 #[non_exhaustive]
-enum Exhaustive {
+pub enum Exhaustive {
     Foo,
     Bar,
     Baz,
     Quux(String),
 }
 
+// no warning, already non_exhaustive
 #[non_exhaustive]
-enum NonExhaustive {
+pub enum NonExhaustive {
+    Foo,
+    Bar,
+    Baz,
+    Quux(String),
+}
+
+// no warning, private
+enum ExhaustivePrivate {
+    Foo,
+    Bar,
+    Baz,
+    Quux(String),
+}
+
+// no warning, private
+#[non_exhaustive]
+enum NonExhaustivePrivate {
     Foo,
     Bar,
     Baz,

tests/ui/exhaustive_enums.rs

@@ -7,15 +7,33 @@ fn main() {
     // nop
 }
 
-enum Exhaustive {
+pub enum Exhaustive {
     Foo,
     Bar,
     Baz,
     Quux(String),
 }
 
+// no warning, already non_exhaustive
 #[non_exhaustive]
-enum NonExhaustive {
+pub enum NonExhaustive {
+    Foo,
+    Bar,
+    Baz,
+    Quux(String),
+}
+
+// no warning, private
+enum ExhaustivePrivate {
+    Foo,
+    Bar,
+    Baz,
+    Quux(String),
+}
+
+// no warning, private
+#[non_exhaustive]
+enum NonExhaustivePrivate {
     Foo,
     Bar,
     Baz,

tests/ui/exhaustive_enums.stderr

 error: enums should not be exhaustive
   --> $DIR/exhaustive_enums.rs:10:1
    |
-LL | / enum Exhaustive {
+LL | / pub enum Exhaustive {
 LL | |     Foo,
 LL | |     Bar,
 LL | |     Baz,
@@ -17,7 +17,7 @@ LL | #![deny(clippy::exhaustive_enums)]
 help: try adding #[non_exhaustive]
    |
 LL | #[non_exhaustive]
-LL | enum Exhaustive {
+LL | pub enum Exhaustive {
 LL |     Foo,
 LL |     Bar,
 LL |     Baz,