From b82171de5fe2a13a12f35ce4368ef34a477f55c4 Mon Sep 17 00:00:00 2001
From: Jana Dönszelmann <jana@donsz.nl>
Date: Sun, 24 Aug 2025 13:19:31 +0200
Subject: port `#[pattern_complexity_limit]` to the new attribute parsing
 infrastructure

---
 .../src/attributes/crate_level.rs                  | 27 ++++++++++++++++++++++
 compiler/rustc_attr_parsing/src/context.rs         |  4 +++-
 2 files changed, 30 insertions(+), 1 deletion(-)

(limited to 'compiler/rustc_attr_parsing/src')

diff --git a/compiler/rustc_attr_parsing/src/attributes/crate_level.rs b/compiler/rustc_attr_parsing/src/attributes/crate_level.rs
index 34793a7f403..6fd4a4a753b 100644
--- a/compiler/rustc_attr_parsing/src/attributes/crate_level.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/crate_level.rs
@@ -147,3 +147,30 @@ impl<S: Stage> SingleAttributeParser<S> for TypeLengthLimitParser {
         })
     }
 }
+
+pub(crate) struct PatternComplexityLimitParser;
+
+impl<S: Stage> SingleAttributeParser<S> for PatternComplexityLimitParser {
+    const PATH: &[Symbol] = &[sym::pattern_complexity_limit];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const TEMPLATE: AttributeTemplate = template!(NameValueStr: "N");
+    const TYPE: AttributeType = AttributeType::CrateLevel;
+
+    // FIXME: recursion limit is allowed on all targets and ignored,
+    //        even though it should only be valid on crates of course
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Crate)]);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let ArgParser::NameValue(nv) = args else {
+            cx.expected_name_value(cx.attr_span, None);
+            return None;
+        };
+
+        Some(AttributeKind::PatternComplexityLimit {
+            limit: cx.parse_limit_int(nv)?,
+            attr_span: cx.attr_span,
+            limit_span: nv.value_span,
+        })
+    }
+}
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 25a1993d089..fc41e38c797 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -25,7 +25,8 @@ use crate::attributes::codegen_attrs::{
 };
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::crate_level::{
-    CrateNameParser, MoveSizeLimitParser, RecursionLimitParser, TypeLengthLimitParser,
+    CrateNameParser, MoveSizeLimitParser, PatternComplexityLimitParser, RecursionLimitParser,
+    TypeLengthLimitParser,
 };
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::dummy::DummyParser;
@@ -187,6 +188,7 @@ attribute_parsers!(
         Single<MustUseParser>,
         Single<OptimizeParser>,
         Single<PathAttributeParser>,
+        Single<PatternComplexityLimitParser>,
         Single<ProcMacroDeriveParser>,
         Single<RecursionLimitParser>,
         Single<RustcBuiltinMacroParser>,
-- 
cgit 1.4.1-3-g733a5