1 files changed, 111 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/exhaustive_items.rs b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
new file mode 100644
index 000000000..173d41b4b
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
@@ -0,0 +1,111 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::indent_of;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+declare_clippy_lint! {
+    /// ### 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 exported enums may wish to
+    /// disable them by default.
+    ///
+    /// ### Example
+    /// ```rust
+    /// enum Foo {
+    ///     Bar,
+    ///     Baz
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// #[non_exhaustive]
+    /// enum Foo {
+    ///     Bar,
+    ///     Baz
+    /// }
+    /// ```
+    #[clippy::version = "1.51.0"]
+    pub EXHAUSTIVE_ENUMS,
+    restriction,
+    "detects exported enums that have not been marked #[non_exhaustive]"
+}
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Warns on any exported `structs`s that are not tagged `#[non_exhaustive]`
+    ///
+    /// ### Why is this bad?
+    /// Exhaustive structs are typically fine, but a project which does
+    /// not wish to make a stability commitment around exported structs may wish to
+    /// disable them by default.
+    ///
+    /// ### Example
+    /// ```rust
+    /// struct Foo {
+    ///     bar: u8,
+    ///     baz: String,
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// #[non_exhaustive]
+    /// struct Foo {
+    ///     bar: u8,
+    ///     baz: String,
+    /// }
+    /// ```
+    #[clippy::version = "1.51.0"]
+    pub EXHAUSTIVE_STRUCTS,
+    restriction,
+    "detects exported structs that have not been marked #[non_exhaustive]"
+}
+
+declare_lint_pass!(ExhaustiveItems => [EXHAUSTIVE_ENUMS, EXHAUSTIVE_STRUCTS]);
+
+impl LateLintPass<'_> for ExhaustiveItems {
+    fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+        if_chain! {
+            if let ItemKind::Enum(..) | ItemKind::Struct(..) = item.kind;
+            if cx.access_levels.is_exported(item.def_id);
+            let attrs = cx.tcx.hir().attrs(item.hir_id());
+            if !attrs.iter().any(|a| a.has_name(sym::non_exhaustive));
+            then {
+                let (lint, msg) = if let ItemKind::Struct(ref v, ..) = item.kind {
+                    if v.fields().iter().any(|f| {
+                        let def_id = cx.tcx.hir().local_def_id(f.hir_id);
+                        !cx.tcx.visibility(def_id).is_public()
+                    }) {
+                        // skip structs with private fields
+                        return;
+                    }
+                    (EXHAUSTIVE_STRUCTS, "exported structs should not be exhaustive")
+                } else {
+                    (EXHAUSTIVE_ENUMS, "exported enums should not be exhaustive")
+                };
+                let suggestion_span = item.span.shrink_to_lo();
+                let indent = " ".repeat(indent_of(cx, item.span).unwrap_or(0));
+                span_lint_and_then(
+                    cx,
+                    lint,
+                    item.span,
+                    msg,
+                    |diag| {
+                        let sugg = format!("#[non_exhaustive]\n{}", indent);
+                        diag.span_suggestion(suggestion_span,
+                                             "try adding #[non_exhaustive]",
+                                             sugg,
+                                             Applicability::MaybeIncorrect);
+                    }
+                );
+
+            }
+        }
+    }
+}