[Typechecker] Check conforming protocols of context when resolving a custom attribute

lib/AST/NameLookup.cpp

@@ -1835,7 +1835,9 @@ static DirectlyReferencedTypeDecls
 directReferencesForUnqualifiedTypeLookup(DeclName name,
                                          SourceLoc loc, DeclContext *dc) {
   DirectlyReferencedTypeDecls results;
-  UnqualifiedLookup::Options options = UnqualifiedLookup::Flags::TypeLookup;
+  UnqualifiedLookup::Options options =
+      UnqualifiedLookup::Flags::TypeLookup |
+      UnqualifiedLookup::Flags::AllowProtocolMembers;
   UnqualifiedLookup lookup(name, dc, loc, options);
   for (const auto &result : lookup.Results) {
     if (auto typeDecl = dyn_cast<TypeDecl>(result.getValueDecl()))

test/decl/var/property_wrappers.swift

@@ -1519,3 +1519,65 @@ func test_missing_method_with_lvalue_base() {
     }
   }
 }
+
+// SR-11288
+// Look into the protocols that the type conforms to
+
+// typealias as propertyWrapper //
+
+@propertyWrapper
+struct SR_11288_S0 {
+  var wrappedValue: Int
+}
+
+protocol SR_11288_P1 {
+  typealias SR_11288_Wrapper1 = SR_11288_S0
+}
+
+struct SR_11288_S1: SR_11288_P1 {
+  @SR_11288_Wrapper1 var answer = 42 // Okay
+}
+
+// associatedtype as propertyWrapper //
+
+protocol SR_11288_P2 {
+  associatedtype SR_11288_Wrapper2 = SR_11288_S0
+}
+
+struct SR_11288_S2: SR_11288_P2 {
+  @SR_11288_Wrapper2 var answer = 42 // expected-error {{unknown attribute 'SR_11288_Wrapper2'}}
+}
+
+protocol SR_11288_P3 {
+  associatedtype SR_11288_Wrapper3
+}
+
+struct SR_11288_S3: SR_11288_P3 {
+  typealias SR_11288_Wrapper3 = SR_11288_S0
+  @SR_11288_Wrapper3 var answer = 42 // Okay
+}
+
+// typealias as propertyWrapper in a constrained protocol extension //
+
+protocol SR_11288_P4 {}
+extension SR_11288_P4 where Self: AnyObject {
+  typealias SR_11288_Wrapper4 = SR_11288_S0
+}
+
+struct SR_11288_S4: SR_11288_P4 {
+  @SR_11288_Wrapper4 var answer = 42 // expected-error 2 {{'SR_11288_S4.SR_11288_Wrapper4.Type' (aka 'SR_11288_S0.Type') requires that 'SR_11288_S4' conform to 'AnyObject'}}
+}
+
+class SR_11288_C0: SR_11288_P4 {
+  @SR_11288_Wrapper4 var answer = 42 // Okay
+}
+
+// typealias as propertyWrapper in a generic type //
+
+protocol SR_11288_P5 {
+  typealias SR_11288_Wrapper5 = SR_11288_S0
+}
+
+struct SR_11288_S5<T>: SR_11288_P5 {
+  @SR_11288_Wrapper5 var answer = 42 // Okay
+}