text: // RUN: %clang_cc1 -triple x86_64-unknown-unknown -std=c++11 -verify %s
  
  // Error cases.
  
  [[gnu::this_attribute_does_not_exist]] int unknown_attr;
  // expected-warning@-1 {{unknown attribute 'this_attribute_does_not_exist' ignored}}
  int [[gnu::unused]] attr_on_type;
  // expected-error@-1 {{'unused' attribute cannot be applied to types}}
  int *[[gnu::unused]] attr_on_ptr;
  // expected-warning@-1 {{attribute 'unused' ignored, because it cannot be applied to a type}}
  [[gnu::fastcall]] void pr17424_1();
  // expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
  [[gnu::fastcall]] [[gnu::stdcall]] void pr17424_2();
  // expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
  // expected-warning@-2 {{calling convention 'stdcall' ignored for this target}}
  [[gnu::fastcall]] __stdcall void pr17424_3();
  // expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
  // expected-warning@-2 {{calling convention '__stdcall' ignored for this target}}
  [[gnu::fastcall]] void pr17424_4() [[gnu::stdcall]];
  // expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
  // expected-warning@-2 {{attribute 'stdcall' ignored, because it cannot be applied to a type}}
  void pr17424_5 [[gnu::fastcall]]();
  // expected-warning@-1 {{calling convention 'fastcall' ignored for this target}}
  
  // Valid cases.
  
  void aliasb [[gnu::alias("_Z6alias1v")]] ();
  void alias1() {}
  void aliasa [[gnu::alias("_Z6alias1v")]] ();
  
  extern struct PR22493Ty {
  } PR22493 [[gnu::alias("_ZN7pcrecpp2RE6no_argE")]];
  
  [[gnu::aligned(8)]] int aligned;
  void aligned_fn [[gnu::aligned(32)]] ();
  struct [[gnu::aligned(8)]] aligned_struct {};
  
  void always_inline [[gnu::always_inline]] ();
  
  __thread int tls_model [[gnu::tls_model("local-exec")]];
  
  void cleanup(int *p) {
    int n [[gnu::cleanup(cleanup)]];
  }
  
  void deprecated1 [[gnu::deprecated]] (); // expected-note {{here}}
  [[gnu::deprecated("custom message")]] void deprecated2(); // expected-note {{here}}
  void deprecated3() {
    deprecated1(); // expected-warning {{deprecated}}
    deprecated2(); // expected-warning {{custom message}}
  }
  
  [[gnu::naked(1,2,3)]] void naked(); // expected-error {{takes no arguments}}
  
  void nonnull [[gnu::nonnull]] (); // expected-warning {{applied to function with no pointer arguments}}
  
  // [[gnu::noreturn]] appertains to a declaration, and marks the innermost
  // function declarator in that declaration as being noreturn.
  int noreturn [[gnu::noreturn]]; // expected-warning {{'noreturn' only applies to function types}}
  int noreturn_fn_1();
  int noreturn_fn_2() [[gnu::noreturn]]; // expected-warning {{cannot be applied to a type}}
  int noreturn_fn_3 [[gnu::noreturn]] ();
  [[gnu::noreturn]] int noreturn_fn_4();
  int (*noreturn_fn_ptr_1 [[gnu::noreturn]])() = &noreturn_fn_1; // expected-error {{cannot initialize}}
  int (*noreturn_fn_ptr_2 [[gnu::noreturn]])() = &noreturn_fn_3;
  [[gnu::noreturn]] int (*noreturn_fn_ptr_3)() = &noreturn_fn_1; // expected-error {{cannot initialize}}
  [[gnu::noreturn]] int (*noreturn_fn_ptr_4)() = &noreturn_fn_3;
  
  struct [[gnu::packed]] packed { char c; int n; };
  static_assert(sizeof(packed) == sizeof(char) + sizeof(int), "not packed");
  