Auto merge of #13345 - Alexendoo:manual-non-exhaustive-visibility, r=y21

Only lint `manual_non_exhaustive` for exported types

For types that are not exported the attribute doesn't make a difference, but the manual pattern can still be used to achieve module level non exhaustiveness

Fixes #10301
Fixes #12106

changelog: none

Author: bors

clippy_lints/src/lib.rs

@@ -634,8 +634,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
     let format_args = format_args_storage.clone();
     store.register_late_pass(move |_| Box::new(methods::Methods::new(conf, format_args.clone())));
     store.register_late_pass(move |_| Box::new(matches::Matches::new(conf)));
-    store.register_early_pass(move || Box::new(manual_non_exhaustive::ManualNonExhaustiveStruct::new(conf)));
-    store.register_late_pass(move |_| Box::new(manual_non_exhaustive::ManualNonExhaustiveEnum::new(conf)));
+    store.register_late_pass(move |_| Box::new(manual_non_exhaustive::ManualNonExhaustive::new(conf)));
     store.register_late_pass(move |_| Box::new(manual_strip::ManualStrip::new(conf)));
     store.register_early_pass(move || Box::new(redundant_static_lifetimes::RedundantStaticLifetimes::new(conf)));
     store.register_early_pass(move || Box::new(redundant_field_names::RedundantFieldNames::new(conf)));

clippy_lints/src/manual_non_exhaustive.rs

@@ -2,16 +2,16 @@ use clippy_config::msrvs::{self, Msrv};
 use clippy_config::Conf;
 use clippy_utils::diagnostics::{span_lint_and_then, span_lint_hir_and_then};
 use clippy_utils::is_doc_hidden;
-use clippy_utils::source::SpanRangeExt;
-use rustc_ast::ast::{self, VisibilityKind};
+use clippy_utils::source::snippet_indent;
+use itertools::Itertools;
 use rustc_ast::attr;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
-use rustc_hir::{self as hir, Expr, ExprKind, QPath};
-use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_hir::{Expr, ExprKind, Item, ItemKind, QPath, TyKind, VariantData};
+use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::impl_lint_pass;
-use rustc_span::def_id::{DefId, LocalDefId};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
@@ -62,29 +62,13 @@ declare_clippy_lint! {
     "manual implementations of the non-exhaustive pattern can be simplified using #[non_exhaustive]"
 }
 
-#[expect(clippy::module_name_repetitions)]
-pub struct ManualNonExhaustiveStruct {
+pub struct ManualNonExhaustive {
     msrv: Msrv,
-}
-
-impl ManualNonExhaustiveStruct {
-    pub fn new(conf: &'static Conf) -> Self {
-        Self {
-            msrv: conf.msrv.clone(),
-        }
-    }
-}
-
-impl_lint_pass!(ManualNonExhaustiveStruct => [MANUAL_NON_EXHAUSTIVE]);
-
-#[expect(clippy::module_name_repetitions)]
-pub struct ManualNonExhaustiveEnum {
-    msrv: Msrv,
-    constructed_enum_variants: FxHashSet<(DefId, DefId)>,
+    constructed_enum_variants: FxHashSet<LocalDefId>,
     potential_enums: Vec<(LocalDefId, LocalDefId, Span, Span)>,
 }
 
-impl ManualNonExhaustiveEnum {
+impl ManualNonExhaustive {
     pub fn new(conf: &'static Conf) -> Self {
         Self {
             msrv: conf.msrv.clone(),
@@ -94,96 +78,78 @@ impl ManualNonExhaustiveEnum {
     }
 }
 
-impl_lint_pass!(ManualNonExhaustiveEnum => [MANUAL_NON_EXHAUSTIVE]);
-
-impl EarlyLintPass for ManualNonExhaustiveStruct {
-    fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
-        if let ast::ItemKind::Struct(variant_data, _) = &item.kind
-            && let (fields, delimiter) = match variant_data {
-                ast::VariantData::Struct { fields, .. } => (&**fields, '{'),
-                ast::VariantData::Tuple(fields, _) => (&**fields, '('),
-                ast::VariantData::Unit(_) => return,
-            }
-            && fields.len() > 1
-            && self.msrv.meets(msrvs::NON_EXHAUSTIVE)
-        {
-            let mut iter = fields.iter().filter_map(|f| match f.vis.kind {
-                VisibilityKind::Public => None,
-                VisibilityKind::Inherited => Some(Ok(f)),
-                VisibilityKind::Restricted { .. } => Some(Err(())),
-            });
-            if let Some(Ok(field)) = iter.next()
-                && iter.next().is_none()
-                && field.ty.kind.is_unit()
-            {
-                span_lint_and_then(
-                    cx,
-                    MANUAL_NON_EXHAUSTIVE,
-                    item.span,
-                    "this seems like a manual implementation of the non-exhaustive pattern",
-                    |diag| {
-                        if !item.attrs.iter().any(|attr| attr.has_name(sym::non_exhaustive))
-                            && let header_span = cx.sess().source_map().span_until_char(item.span, delimiter)
-                            && let Some(snippet) = header_span.get_source_text(cx)
-                        {
-                            diag.span_suggestion(
-                                header_span,
-                                "add the attribute",
-                                format!("#[non_exhaustive] {snippet}"),
-                                Applicability::Unspecified,
-                            );
-                        }
-                        diag.span_help(field.span, "remove this field");
-                    },
-                );
-            }
-        }
-    }
+impl_lint_pass!(ManualNonExhaustive => [MANUAL_NON_EXHAUSTIVE]);
 
-    extract_msrv_attr!(EarlyContext);
-}
-
-impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
-    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
-        if !self.msrv.meets(msrvs::NON_EXHAUSTIVE) {
+impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustive {
+    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+        if !self.msrv.meets(msrvs::NON_EXHAUSTIVE) || !cx.effective_visibilities.is_exported(item.owner_id.def_id) {
             return;
         }
 
-        if let hir::ItemKind::Enum(def, _) = &item.kind
-            && def.variants.len() > 1
-        {
-            let mut iter = def.variants.iter().filter_map(|v| {
-                (matches!(v.data, hir::VariantData::Unit(_, _))
-                    && is_doc_hidden(cx.tcx.hir().attrs(v.hir_id))
-                    && !attr::contains_name(cx.tcx.hir().attrs(item.hir_id()), sym::non_exhaustive))
-                .then_some((v.def_id, v.span))
-            });
-            if let Some((id, span)) = iter.next()
-                && iter.next().is_none()
-            {
-                self.potential_enums.push((item.owner_id.def_id, id, item.span, span));
-            }
+        match item.kind {
+            ItemKind::Enum(def, _) if def.variants.len() > 1 => {
+                let iter = def.variants.iter().filter_map(|v| {
+                    (matches!(v.data, VariantData::Unit(_, _)) && is_doc_hidden(cx.tcx.hir().attrs(v.hir_id)))
+                        .then_some((v.def_id, v.span))
+                });
+                if let Ok((id, span)) = iter.exactly_one()
+                    && !attr::contains_name(cx.tcx.hir().attrs(item.hir_id()), sym::non_exhaustive)
+                {
+                    self.potential_enums.push((item.owner_id.def_id, id, item.span, span));
+                }
+            },
+            ItemKind::Struct(variant_data, _) => {
+                let fields = variant_data.fields();
+                let private_fields = fields
+                    .iter()
+                    .filter(|field| !cx.effective_visibilities.is_exported(field.def_id));
+                if fields.len() > 1
+                    && let Ok(field) = private_fields.exactly_one()
+                    && let TyKind::Tup([]) = field.ty.kind
+                {
+                    span_lint_and_then(
+                        cx,
+                        MANUAL_NON_EXHAUSTIVE,
+                        item.span,
+                        "this seems like a manual implementation of the non-exhaustive pattern",
+                        |diag| {
+                            if let Some(non_exhaustive) =
+                                attr::find_by_name(cx.tcx.hir().attrs(item.hir_id()), sym::non_exhaustive)
+                            {
+                                diag.span_note(non_exhaustive.span, "the struct is already non-exhaustive");
+                            } else {
+                                let indent = snippet_indent(cx, item.span).unwrap_or_default();
+                                diag.span_suggestion_verbose(
+                                    item.span.shrink_to_lo(),
+                                    "use the `#[non_exhaustive]` attribute instead",
+                                    format!("#[non_exhaustive]\n{indent}"),
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
+                            diag.span_help(field.span, "remove this field");
+                        },
+                    );
+                }
+            },
+            _ => {},
         }
     }
 
     fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         if let ExprKind::Path(QPath::Resolved(None, p)) = &e.kind
-            && let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), id) = p.res
+            && let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), ctor_id) = p.res
+            && let Some(local_ctor) = ctor_id.as_local()
         {
-            let variant_id = cx.tcx.parent(id);
-            let enum_id = cx.tcx.parent(variant_id);
-
-            self.constructed_enum_variants.insert((enum_id, variant_id));
+            let variant_id = cx.tcx.local_parent(local_ctor);
+            self.constructed_enum_variants.insert(variant_id);
         }
     }
 
     fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
-        for &(enum_id, _, enum_span, variant_span) in
-            self.potential_enums.iter().filter(|&&(enum_id, variant_id, _, _)| {
-                !self
-                    .constructed_enum_variants
-                    .contains(&(enum_id.to_def_id(), variant_id.to_def_id()))
-            })
+        for &(enum_id, _, enum_span, variant_span) in self
+            .potential_enums
+            .iter()
+            .filter(|(_, variant_id, _, _)| !self.constructed_enum_variants.contains(variant_id))
         {
             let hir_id = cx.tcx.local_def_id_to_hir_id(enum_id);
             span_lint_hir_and_then(
@@ -193,15 +159,13 @@ impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {
                 enum_span,
                 "this seems like a manual implementation of the non-exhaustive pattern",
                 |diag| {
-                    let header_span = cx.sess().source_map().span_until_char(enum_span, '{');
-                    if let Some(snippet) = header_span.get_source_text(cx) {
-                        diag.span_suggestion(
-                            header_span,
-                            "add the attribute",
-                            format!("#[non_exhaustive] {snippet}"),
-                            Applicability::Unspecified,
-                        );
-                    }
+                    let indent = snippet_indent(cx, enum_span).unwrap_or_default();
+                    diag.span_suggestion_verbose(
+                        enum_span.shrink_to_lo(),
+                        "use the `#[non_exhaustive]` attribute instead",
+                        format!("#[non_exhaustive]\n{indent}"),
+                        Applicability::MaybeIncorrect,
+                    );
                     diag.span_help(variant_span, "remove this variant");
                 },
             );

tests/ui/manual_non_exhaustive_enum.rs

@@ -1,8 +1,8 @@
 #![warn(clippy::manual_non_exhaustive)]
 #![allow(unused)]
 //@no-rustfix
-enum E {
-    //~^ ERROR: this seems like a manual implementation of the non-exhaustive pattern
+pub enum E {
+    //~^ manual_non_exhaustive
     A,
     B,
     #[doc(hidden)]
@@ -11,44 +11,44 @@ enum E {
 
 // if the user explicitly marks as nonexhaustive we shouldn't warn them
 #[non_exhaustive]
-enum Ep {
+pub enum Ep {
     A,
     B,
     #[doc(hidden)]
     _C,
 }
 
 // marker variant does not have doc hidden attribute, should be ignored
-enum NoDocHidden {
+pub enum NoDocHidden {
     A,
     B,
     _C,
 }
 
 // name of variant with doc hidden does not start with underscore
-enum NoUnderscore {
+pub enum NoUnderscore {
     A,
     B,
     #[doc(hidden)]
     C,
 }
 
 // variant with doc hidden is not unit, should be ignored
-enum NotUnit {
+pub enum NotUnit {
     A,
     B,
     #[doc(hidden)]
     _C(bool),
 }
 
 // variant with doc hidden is the only one, should be ignored
-enum OnlyMarker {
+pub enum OnlyMarker {
     #[doc(hidden)]
     _A,
 }
 
 // variant with multiple markers, should be ignored
-enum MultipleMarkers {
+pub enum MultipleMarkers {
     A,
     #[doc(hidden)]
     _B,
@@ -58,13 +58,13 @@ enum MultipleMarkers {
 
 // already non_exhaustive and no markers, should be ignored
 #[non_exhaustive]
-enum NonExhaustive {
+pub enum NonExhaustive {
     A,
     B,
 }
 
 // marked is used, don't lint
-enum UsedHidden {
+pub enum UsedHidden {
     #[doc(hidden)]
     _A,
     B,
@@ -77,11 +77,9 @@ fn foo(x: &mut UsedHidden) {
 }
 
 #[expect(clippy::manual_non_exhaustive)]
-enum ExpectLint {
+pub enum ExpectLint {
     A,
     B,
     #[doc(hidden)]
     _C,
 }
-
-fn main() {}

tests/ui/manual_non_exhaustive_enum.stderr

@@ -1,11 +1,7 @@
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_enum.rs:4:1
    |
-LL |   enum E {
-   |   ^-----
-   |   |
-   |  _help: add the attribute: `#[non_exhaustive] enum E`
-   | |
+LL | / pub enum E {
 LL | |
 LL | |     A,
 LL | |     B,
@@ -21,15 +17,16 @@ LL |     _C,
    |     ^^
    = note: `-D clippy::manual-non-exhaustive` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::manual_non_exhaustive)]`
+help: use the `#[non_exhaustive]` attribute instead
+   |
+LL + #[non_exhaustive]
+LL | pub enum E {
+   |
 
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_enum.rs:29:1
    |
-LL |   enum NoUnderscore {
-   |   ^----------------
-   |   |
-   |  _help: add the attribute: `#[non_exhaustive] enum NoUnderscore`
-   | |
+LL | / pub enum NoUnderscore {
 LL | |     A,
 LL | |     B,
 LL | |     #[doc(hidden)]
@@ -42,6 +39,11 @@ help: remove this variant
    |
 LL |     C,
    |     ^
+help: use the `#[non_exhaustive]` attribute instead
+   |
+LL + #[non_exhaustive]
+LL | pub enum NoUnderscore {
+   |
 
 error: aborting due to 2 previous errors
 

tests/ui/manual_non_exhaustive_struct.rs

@@ -1,78 +1,86 @@
 #![warn(clippy::manual_non_exhaustive)]
 #![allow(unused)]
 //@no-rustfix
-mod structs {
-    struct S {
-        //~^ ERROR: this seems like a manual implementation of the non-exhaustive pattern
+pub mod structs {
+    pub struct S {
+        //~^ manual_non_exhaustive
         pub a: i32,
         pub b: i32,
         _c: (),
     }
 
     // user forgot to remove the private field
     #[non_exhaustive]
-    struct Sp {
-        //~^ ERROR: this seems like a manual implementation of the non-exhaustive pattern
+    pub struct Sp {
+        //~^ manual_non_exhaustive
         pub a: i32,
         pub b: i32,
         _c: (),
     }
 
     // some other fields are private, should be ignored
-    struct PrivateFields {
+    pub struct PrivateFields {
         a: i32,
         pub b: i32,
         _c: (),
     }
 
-    // private field name does not start with underscore, should be ignored
-    struct NoUnderscore {
+    pub struct NoUnderscore {
+        //~^ manual_non_exhaustive
         pub a: i32,
         pub b: i32,
         c: (),
     }
 
     // private field is not unit type, should be ignored
-    struct NotUnit {
+    pub struct NotUnit {
         pub a: i32,
         pub b: i32,
         _c: i32,
     }
 
     // private field is the only field, should be ignored
-    struct OnlyMarker {
+    pub struct OnlyMarker {
         _a: (),
     }
 
     // already non exhaustive and no private fields, should be ignored
     #[non_exhaustive]
-    struct NonExhaustive {
+    pub struct NonExhaustive {
         pub a: i32,
         pub b: i32,
     }
 }
 
-mod tuple_structs {
-    struct T(pub i32, pub i32, ());
-    //~^ ERROR: this seems like a manual implementation of the non-exhaustive pattern
+pub mod tuple_structs {
+    pub struct T(pub i32, pub i32, ());
+    //~^ manual_non_exhaustive
 
     // user forgot to remove the private field
     #[non_exhaustive]
-    struct Tp(pub i32, pub i32, ());
-    //~^ ERROR: this seems like a manual implementation of the non-exhaustive pattern
+    pub struct Tp(pub i32, pub i32, ());
+    //~^ manual_non_exhaustive
 
     // some other fields are private, should be ignored
-    struct PrivateFields(pub i32, i32, ());
+    pub struct PrivateFields(pub i32, i32, ());
 
     // private field is not unit type, should be ignored
-    struct NotUnit(pub i32, pub i32, i32);
+    pub struct NotUnit(pub i32, pub i32, i32);
 
     // private field is the only field, should be ignored
-    struct OnlyMarker(());
+    pub struct OnlyMarker(());
 
     // already non exhaustive and no private fields, should be ignored
     #[non_exhaustive]
-    struct NonExhaustive(pub i32, pub i32);
+    pub struct NonExhaustive(pub i32, pub i32);
 }
 
-fn main() {}
+mod private {
+    // Don't lint structs that are not actually public as `#[non_exhaustive]` only applies to
+    // external crates. The manual pattern can still be used to get module local non exhaustiveness
+    pub struct NotPublic {
+        pub a: i32,
+        pub b: i32,
+        _c: (),
+    }
+}

tests/ui/manual_non_exhaustive_struct.stderr

@@ -1,11 +1,7 @@
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_struct.rs:5:5
    |
-LL |       struct S {
-   |       ^-------
-   |       |
-   |  _____help: add the attribute: `#[non_exhaustive] struct S`
-   | |
+LL | /     pub struct S {
 LL | |
 LL | |         pub a: i32,
 LL | |         pub b: i32,
@@ -20,32 +16,39 @@ LL |         _c: (),
    |         ^^^^^^
    = note: `-D clippy::manual-non-exhaustive` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::manual_non_exhaustive)]`
+help: use the `#[non_exhaustive]` attribute instead
+   |
+LL ~     #[non_exhaustive]
+LL ~     pub struct S {
+   |
 
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_struct.rs:14:5
    |
-LL | /     struct Sp {
+LL | /     pub struct Sp {
 LL | |
 LL | |         pub a: i32,
 LL | |         pub b: i32,
 LL | |         _c: (),
 LL | |     }
    | |_____^
    |
+note: the struct is already non-exhaustive
+  --> tests/ui/manual_non_exhaustive_struct.rs:13:5
+   |
+LL |     #[non_exhaustive]
+   |     ^^^^^^^^^^^^^^^^^
 help: remove this field
   --> tests/ui/manual_non_exhaustive_struct.rs:18:9
    |
 LL |         _c: (),
    |         ^^^^^^
 
 error: this seems like a manual implementation of the non-exhaustive pattern
-  --> tests/ui/manual_non_exhaustive_struct.rs:29:5
+  --> tests/ui/manual_non_exhaustive_struct.rs:28:5
    |
-LL |       struct NoUnderscore {
-   |       ^------------------
-   |       |
-   |  _____help: add the attribute: `#[non_exhaustive] struct NoUnderscore`
-   | |
+LL | /     pub struct NoUnderscore {
+LL | |
 LL | |         pub a: i32,
 LL | |         pub b: i32,
 LL | |         c: (),
@@ -57,32 +60,45 @@ help: remove this field
    |
 LL |         c: (),
    |         ^^^^^
+help: use the `#[non_exhaustive]` attribute instead
+   |
+LL ~     #[non_exhaustive]
+LL ~     pub struct NoUnderscore {
+   |
 
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_struct.rs:56:5
    |
-LL |     struct T(pub i32, pub i32, ());
-   |     --------^^^^^^^^^^^^^^^^^^^^^^^
-   |     |
-   |     help: add the attribute: `#[non_exhaustive] struct T`
+LL |     pub struct T(pub i32, pub i32, ());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove this field
-  --> tests/ui/manual_non_exhaustive_struct.rs:56:32
+  --> tests/ui/manual_non_exhaustive_struct.rs:56:36
+   |
+LL |     pub struct T(pub i32, pub i32, ());
+   |                                    ^^
+help: use the `#[non_exhaustive]` attribute instead
+   |
+LL ~     #[non_exhaustive]
+LL ~     pub struct T(pub i32, pub i32, ());
    |
-LL |     struct T(pub i32, pub i32, ());
-   |                                ^^
 
 error: this seems like a manual implementation of the non-exhaustive pattern
   --> tests/ui/manual_non_exhaustive_struct.rs:61:5
    |
-LL |     struct Tp(pub i32, pub i32, ());
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     pub struct Tp(pub i32, pub i32, ());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the struct is already non-exhaustive
+  --> tests/ui/manual_non_exhaustive_struct.rs:60:5
    |
+LL |     #[non_exhaustive]
+   |     ^^^^^^^^^^^^^^^^^
 help: remove this field
-  --> tests/ui/manual_non_exhaustive_struct.rs:61:33
+  --> tests/ui/manual_non_exhaustive_struct.rs:61:37
    |
-LL |     struct Tp(pub i32, pub i32, ());
-   |                                 ^^
+LL |     pub struct Tp(pub i32, pub i32, ());
+   |                                     ^^
 
 error: aborting due to 5 previous errors