clang/test/Sema/attr-ownership.cpp

// RUN: %clang_cc1 %s -verify -fsyntax-only

class C {
  void f(int, int)
      __attribute__((ownership_returns(foo, 2)))  // expected-note {{declared with index 2 here}}
      __attribute__((ownership_returns(foo, 3))); // expected-error {{'ownership_returns' attribute index does not match; here it is 3}}
};