Fix lints duplications in unknown_attribute and renamed_builtin_attr

clippy_lints/src/attrs/mod.rs

@@ -14,11 +14,12 @@ mod useless_attribute;
 mod utils;
 
 use clippy_config::Conf;
+use clippy_utils::check_clippy_attr;
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::msrvs::{self, Msrv, MsrvStack};
 use rustc_ast::{self as ast, AttrArgs, AttrItemKind, AttrKind, Attribute, MetaItemInner, MetaItemKind};
 use rustc_hir::{ImplItem, ImplItemKind, Item, ItemKind, TraitFn, TraitItem, TraitItemKind};
-use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 use rustc_session::impl_lint_pass;
 use rustc_span::sym;
 use utils::is_lint_level;
@@ -582,6 +583,7 @@ impl EarlyLintPass for PostExpansionEarlyAttributes {
     }
 
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
+        check_clippy_attr(cx.sess(), attr);
         if let Some(items) = &attr.meta_item_list()
             && let Some(name) = attr.name()
         {

clippy_lints/src/matches/significant_drop_in_scrutinee.rs

@@ -11,7 +11,7 @@ use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::{Applicability, Diag};
 use rustc_hir::intravisit::{Visitor, walk_expr};
 use rustc_hir::{Arm, Expr, ExprKind, MatchSource};
-use rustc_lint::{LateContext, LintContext};
+use rustc_lint::LateContext;
 use rustc_middle::ty::{GenericArgKind, RegionKind, Ty, TypeVisitableExt};
 use rustc_span::Span;
 
@@ -184,7 +184,6 @@ impl<'a, 'tcx> SigDropChecker<'a, 'tcx> {
     fn has_sig_drop_attr_impl(&mut self, ty: Ty<'tcx>) -> bool {
         if let Some(adt) = ty.ty_adt_def()
             && get_builtin_attr(
-                self.cx.sess(),
                 #[allow(deprecated)]
                 self.cx.tcx.get_all_attrs(adt.did()),
                 sym::has_significant_drop,

clippy_lints/src/significant_drop_tightening.rs

@@ -8,7 +8,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::{Visitor, walk_expr};
 use rustc_hir::{self as hir, HirId};
-use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{GenericArgKind, Ty, Unnormalized};
 use rustc_session::impl_lint_pass;
 use rustc_span::symbol::Ident;
@@ -170,7 +170,6 @@ impl<'cx, 'others, 'tcx> AttrChecker<'cx, 'others, 'tcx> {
     fn has_sig_drop_attr_uncached(&mut self, ty: Ty<'tcx>, depth: usize) -> bool {
         if let Some(adt) = ty.ty_adt_def() {
             let mut iter = get_builtin_attr(
-                self.cx.sess(),
                 #[allow(deprecated)]
                 self.cx.tcx.get_all_attrs(adt.did()),
                 sym::has_significant_drop,

clippy_lints/src/utils/author.rs

@@ -9,7 +9,7 @@ use rustc_hir::{
     self as hir, BindingMode, CaptureBy, Closure, ClosureKind, ConstArg, ConstArgKind, CoroutineKind, ExprKind,
     FnRetTy, HirId, Lit, PatExprKind, PatKind, QPath, StmtKind, StructTailExpr,
 };
-use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{FloatTy, IntTy, UintTy};
 use rustc_session::declare_lint_pass;
 use rustc_span::symbol::{Ident, Symbol};
@@ -863,5 +863,5 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
 
 fn has_attr(cx: &LateContext<'_>, hir_id: HirId) -> bool {
     let attrs = cx.tcx.hir_attrs(hir_id);
-    get_builtin_attr(cx.sess(), attrs, sym::author).count() > 0
+    get_builtin_attr(attrs, sym::author).count() > 0
 }

clippy_lints/src/utils/dump_hir.rs

@@ -1,7 +1,7 @@
 use clippy_utils::{get_builtin_attr, sym};
 use hir::TraitItem;
 use rustc_hir as hir;
-use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 
 declare_lint_pass!(
@@ -60,5 +60,5 @@ impl<'tcx> LateLintPass<'tcx> for DumpHir {
 
 fn has_attr(cx: &LateContext<'_>, hir_id: hir::HirId) -> bool {
     let attrs = cx.tcx.hir_attrs(hir_id);
-    get_builtin_attr(cx.sess(), attrs, sym::dump).count() > 0
+    get_builtin_attr(attrs, sym::dump).count() > 0
 }

clippy_utils/src/attrs.rs

@@ -12,51 +12,51 @@ use rustc_session::Session;
 use rustc_span::{Span, Symbol};
 use std::str::FromStr;
 
+/// Validates a single clippy attribute and emits errors for unknown or deprecated ones.
+pub fn check_clippy_attr<A: AttributeExt>(sess: &Session, attr: &A) {
+    if let [clippy, segment2] = &*attr.path()
+        && *clippy == sym::clippy
+    {
+        let path_span = attr
+            .path_span()
+            .expect("Clippy attributes are unparsed and have a span");
+
+        match *segment2 {
+            sym::cyclomatic_complexity => {
+                sess.dcx()
+                    .struct_span_err(path_span, "usage of deprecated attribute")
+                    .with_span_suggestion(
+                        path_span,
+                        "consider using",
+                        "clippy::cognitive_complexity",
+                        Applicability::MachineApplicable,
+                    )
+                    .emit();
+            },
+            sym::author
+            | sym::version
+            | sym::cognitive_complexity
+            | sym::dump
+            | sym::msrv
+            | sym::has_significant_drop
+            | sym::format_args => {},
+            _ => {
+                sess.dcx().span_err(path_span, "usage of unknown attribute");
+            },
+        }
+    }
+}
+
 /// Given `attrs`, extract all the instances of a built-in Clippy attribute called `name`
-pub fn get_builtin_attr<'a, A: AttributeExt + 'a>(
-    sess: &'a Session,
-    attrs: &'a [A],
-    name: Symbol,
-) -> impl Iterator<Item = &'a A> {
+pub fn get_builtin_attr<'a, A: AttributeExt + 'a>(attrs: &'a [A], name: Symbol) -> impl Iterator<Item = &'a A> {
     attrs.iter().filter(move |attr| {
         if let [clippy, segment2] = &*attr.path()
             && *clippy == sym::clippy
         {
-            let path_span = attr
-                .path_span()
-                .expect("Clippy attributes are unparsed and have a span");
-            let new_name = match *segment2 {
-                sym::cyclomatic_complexity => Some("cognitive_complexity"),
-                sym::author
-                | sym::version
-                | sym::cognitive_complexity
-                | sym::dump
-                | sym::msrv
-                // The following attributes are for the 3rd party crate authors.
-                // See book/src/attribs.md
-                | sym::has_significant_drop
-                | sym::format_args => None,
-                _ => {
-                    sess.dcx().span_err(path_span, "usage of unknown attribute");
-                    return false;
-                },
-            };
-
-            match new_name {
-                Some(new_name) => {
-                    sess.dcx()
-                        .struct_span_err(path_span, "usage of deprecated attribute")
-                        .with_span_suggestion(
-                            path_span,
-                            "consider using",
-                            format!("clippy::{new_name}"),
-                            Applicability::MachineApplicable,
-                        )
-                        .emit();
-                    false
-                },
-                None => *segment2 == name,
+            if *segment2 == sym::cyclomatic_complexity {
+                return false;
             }
+            *segment2 == name
         } else {
             false
         }
@@ -67,7 +67,7 @@ pub fn get_builtin_attr<'a, A: AttributeExt + 'a>(
 /// returns that attribute, and `None` otherwise
 pub fn get_unique_builtin_attr<'a, A: AttributeExt>(sess: &'a Session, attrs: &'a [A], name: Symbol) -> Option<&'a A> {
     let mut unique_attr: Option<&A> = None;
-    for attr in get_builtin_attr(sess, attrs, name) {
+    for attr in get_builtin_attr(attrs, name) {
         if let Some(duplicate) = unique_attr {
             sess.dcx()
                 .struct_span_err(attr.span(), format!("`{name}` is defined multiple times"))
@@ -165,7 +165,7 @@ impl LimitStack {
 }
 
 fn parse_attrs<F: FnMut(u64)>(sess: &Session, attrs: &[impl AttributeExt], name: Symbol, mut f: F) {
-    for attr in get_builtin_attr(sess, attrs, name) {
+    for attr in get_builtin_attr(attrs, name) {
         let Some(value) = attr.value_str() else {
             sess.dcx().span_err(attr.span(), "bad clippy attribute");
             continue;

tests/ui/renamed_builtin_attr.fixed

@@ -1,5 +1,3 @@
-//@compile-flags: -Zdeduplicate-diagnostics=yes
-
 #[clippy::cognitive_complexity = "1"]
 //~^ ERROR: usage of deprecated attribute
 fn main() {}

tests/ui/renamed_builtin_attr.rs

@@ -1,5 +1,3 @@
-//@compile-flags: -Zdeduplicate-diagnostics=yes
-
 #[clippy::cyclomatic_complexity = "1"]
 //~^ ERROR: usage of deprecated attribute
 fn main() {}

tests/ui/renamed_builtin_attr.stderr

@@ -1,5 +1,5 @@
 error: usage of deprecated attribute
-  --> tests/ui/renamed_builtin_attr.rs:3:3
+  --> tests/ui/renamed_builtin_attr.rs:1:3
    |
 LL | #[clippy::cyclomatic_complexity = "1"]
    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `clippy::cognitive_complexity`

tests/ui/unknown_attribute.rs

@@ -1,5 +1,3 @@
-//@compile-flags: -Zdeduplicate-diagnostics=yes
-
 #[clippy::unknown]
 //~^ ERROR: usage of unknown attribute
 #[clippy::cognitive_complexity = "1"]

tests/ui/unknown_attribute.stderr

@@ -1,5 +1,5 @@
 error: usage of unknown attribute
-  --> tests/ui/unknown_attribute.rs:3:3
+  --> tests/ui/unknown_attribute.rs:1:3
    |
 LL | #[clippy::unknown]
    |   ^^^^^^^^^^^^^^^