Auto merge of #12190 - alexis-langlet:fix/12035-silence-struct-field-…

…names, r=Manishearth

Fix/12035 silence struct field names

fixes #12035

Allows to silence lints `struct_field_names` and `enum_variant_names` through their impls.
This is done in order for some crates such as `serde` to  silence those lints

changelog: [`struct_field_names`]: allow to silence lint through struct's impl
changelog: [`enum_variant_names`]: allow to silence lint through enum's impl

clippy_lints/src/item_name_repetitions.rs

@@ -1,13 +1,14 @@
 //! lint on enum variants that are prefixed or suffixed by the same characters
 
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_hir};
-use clippy_utils::is_bool;
 use clippy_utils::macros::span_is_local;
 use clippy_utils::source::is_present_in_source;
 use clippy_utils::str_utils::{camel_case_split, count_match_end, count_match_start, to_camel_case, to_snake_case};
+use clippy_utils::{any_impl_has_lint_allowed, is_bool};
 use rustc_hir::{EnumDef, FieldDef, Item, ItemKind, OwnerId, Variant, VariantData};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::impl_lint_pass;
+use rustc_span::def_id::DefId;
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 
@@ -180,7 +181,8 @@ fn have_no_extra_prefix(prefixes: &[&str]) -> bool {
 }
 
 fn check_fields(cx: &LateContext<'_>, threshold: u64, item: &Item<'_>, fields: &[FieldDef<'_>]) {
-    if (fields.len() as u64) < threshold {
+    if (fields.len() as u64) < threshold || any_impl_has_lint_allowed(cx, STRUCT_FIELD_NAMES, item.owner_id.to_def_id())
+    {
         return;
     }
 
@@ -320,8 +322,15 @@ fn check_enum_end(cx: &LateContext<'_>, item_name: &str, variant: &Variant<'_>)
     }
 }
 
-fn check_variant(cx: &LateContext<'_>, threshold: u64, def: &EnumDef<'_>, item_name: &str, span: Span) {
-    if (def.variants.len() as u64) < threshold {
+fn check_variant(
+    cx: &LateContext<'_>,
+    threshold: u64,
+    def: &EnumDef<'_>,
+    item_name: &str,
+    item_did: DefId,
+    span: Span,
+) {
+    if (def.variants.len() as u64) < threshold || any_impl_has_lint_allowed(cx, ENUM_VARIANT_NAMES, item_did) {
         return;
     }
 
@@ -387,6 +396,7 @@ impl LateLintPass<'_> for ItemNameRepetitions {
 
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         let item_name = item.ident.name.as_str();
+
         let item_camel = to_camel_case(item_name);
         if !item.span.from_expansion() && is_present_in_source(cx, item.span) {
             if let [.., (mod_name, mod_camel, owner_id)] = &*self.modules {
@@ -439,7 +449,14 @@ impl LateLintPass<'_> for ItemNameRepetitions {
             && span_is_local(item.span)
         {
             match item.kind {
-                ItemKind::Enum(def, _) => check_variant(cx, self.enum_threshold, &def, item_name, item.span),
+                ItemKind::Enum(def, _) => check_variant(
+                    cx,
+                    self.enum_threshold,
+                    &def,
+                    item_name,
+                    item.owner_id.to_def_id(),
+                    item.span,
+                ),
                 ItemKind::Struct(VariantData::Struct { fields, .. }, _) => {
                     check_fields(cx, self.struct_threshold, item, fields);
                 },

clippy_utils/src/lib.rs

@@ -1819,6 +1819,14 @@ pub fn is_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) ->
     cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow
 }
 
+/// Returns `true` if any of the `impl`s for the given `item` has the lint allowed
+pub fn any_impl_has_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: DefId) -> bool {
+    cx.tcx
+        .inherent_impls(id)
+        .iter()
+        .any(|imp| is_lint_allowed(cx, lint, cx.tcx.hir().expect_item(imp.expect_local()).hir_id()))
+}
+
 pub fn strip_pat_refs<'hir>(mut pat: &'hir Pat<'hir>) -> &'hir Pat<'hir> {
     while let PatKind::Ref(subpat, _) = pat.kind {
         pat = subpat;

tests/ui-toml/item_name_repetitions/threshold5/item_name_repetitions.rs

@@ -29,4 +29,28 @@ enum Foo2 {
     EFoo,
 }
 
+// This should not trigger the lint as one of it's impl has allow attribute
+struct Data3 {
+    a_data: u8,
+    b_data: u8,
+    c_data: u8,
+    d_data: u8,
+    e_data: u8,
+}
+
+#[allow(clippy::struct_field_names)]
+impl Data3 {}
+
+// This should not trigger the lint as one of it's impl has allow attribute
+enum Foo3 {
+    AFoo,
+    BFoo,
+    CFoo,
+    DFoo,
+    EFoo,
+}
+
+#[allow(clippy::enum_variant_names)]
+impl Foo3 {}
+
 fn main() {}