1 // RUN: %clang_cc1 -fcxx-exceptions -fdeclspec -fexceptions -fsyntax-only -verify -std=c++11 -Wc++14-compat -Wc++14-extensions -Wc++17-extensions %s
2 
3 // Need std::initializer_list
4 namespace std {
5   typedef decltype(sizeof(int)) size_t;
6 
7   // libc++'s implementation
8   template <class _E>
9   class initializer_list
10   {
11     const _E* __begin_;
12     size_t    __size_;
13 
14     initializer_list(const _E* __b, size_t __s)
15       : __begin_(__b),
16         __size_(__s)
17     {}
18 
19   public:
20     typedef _E        value_type;
21     typedef const _E& reference;
22     typedef const _E& const_reference;
23     typedef size_t    size_type;
24 
25     typedef const _E* iterator;
26     typedef const _E* const_iterator;
27 
28     initializer_list() : __begin_(nullptr), __size_(0) {}
29 
30     size_t    size()  const {return __size_;}
31     const _E* begin() const {return __begin_;}
32     const _E* end()   const {return __begin_ + __size_;}
33   };
34 }
35 
36 
37 // Declaration syntax checks
38 [[]] int before_attr;
39 int [[]] between_attr;
40 const [[]] int between_attr_2 = 0; // expected-error {{an attribute list cannot appear here}}
41 int after_attr [[]];
42 int * [[]] ptr_attr;
43 int & [[]] ref_attr = after_attr;
44 int & [[unknown]] ref_attr_2 = after_attr; // expected-warning {{unknown attribute 'unknown' ignored}}
45 int & [[noreturn]] ref_attr_3 = after_attr; // expected-error {{'noreturn' attribute cannot be applied to types}}
46 int && [[]] rref_attr = 0;
47 int array_attr [1] [[]];
48 alignas(8) int aligned_attr;
49 [[test::valid(for 42 [very] **** '+' symbols went on a trip and had a "good"_time; the end.)]] int garbage_attr; // expected-warning {{unknown attribute 'valid' ignored}}
50 [[,,,static, class, namespace,, inline, constexpr, mutable,, bitand, bitor::compl(!.*_ Cx.!U^*R),,,]] int more_garbage_attr; // expected-warning {{unknown attribute 'static' ignored}} \
51     // expected-warning {{unknown attribute 'class' ignored}} \
52     // expected-warning {{unknown attribute 'namespace' ignored}} \
53     // expected-warning {{unknown attribute 'inline' ignored}} \
54     // expected-warning {{unknown attribute 'constexpr' ignored}} \
55     // expected-warning {{unknown attribute 'mutable' ignored}} \
56     // expected-warning {{unknown attribute 'bitand' ignored}} \
57     // expected-warning {{unknown attribute 'compl' ignored}}
58 [[u8"invalid!"]] int invalid_string_attr; // expected-error {{expected ']'}}
59 void fn_attr () [[]];
60 void noexcept_fn_attr () noexcept [[]];
61 struct MemberFnOrder {
62   virtual void f() const volatile && noexcept [[]] final = 0;
63 };
64 struct [[]] struct_attr;
65 class [[]] class_attr {};
66 union [[]] union_attr;
67 enum [[]] E { };
68 namespace test_misplacement {
69 [[]] struct struct_attr2;  //expected-error{{misplaced attributes}}
70 [[]] class class_attr2; //expected-error{{misplaced attributes}}
71 [[]] union union_attr2; //expected-error{{misplaced attributes}}
72 [[]] enum  E2 { }; //expected-error{{misplaced attributes}}
73 }
74 
75 // Checks attributes placed at wrong syntactic locations of class specifiers.
76 class [[]] [[]]
77   attr_after_class_name_decl [[]] [[]]; // expected-error {{an attribute list cannot appear here}}
78 
79 class [[]] [[]]
80  attr_after_class_name_definition [[]] [[]] [[]]{}; // expected-error {{an attribute list cannot appear here}}
81 
82 class [[]] c {};
83 class c [[]] [[]] x;
84 class c [[]] [[]] y [[]] [[]];
85 class c final [(int){0}];
86 
87 class base {};
88 class [[]] [[]] final_class
89   alignas(float) [[]] final // expected-error {{an attribute list cannot appear here}}
90   alignas(float) [[]] [[]] alignas(float): base{}; // expected-error {{an attribute list cannot appear here}}
91 
92 class [[]] [[]] final_class_another
93   [[]] [[]] alignas(16) final // expected-error {{an attribute list cannot appear here}}
94   [[]] [[]] alignas(16) [[]]{}; // expected-error {{an attribute list cannot appear here}}
95 
96 // The diagnostics here don't matter much, this just shouldn't crash:
97 class C final [[deprecated(l]] {}); // expected-error {{use of undeclared identifier}} expected-error {{expected ']'}} expected-error {{an attribute list cannot appear here}} expected-error {{expected unqualified-id}}
98 class D final alignas ([l) {}]{}); // expected-error {{expected ',' or ']' in lambda capture list}} expected-error {{an attribute list cannot appear here}}
99 
100 [[]] struct with_init_declarators {} init_declarator;
101 [[]] struct no_init_declarators; // expected-error {{misplaced attributes}}
102 template<typename> [[]] struct no_init_declarators_template; // expected-error {{an attribute list cannot appear here}}
103 void fn_with_structs() {
104   [[]] struct with_init_declarators {} init_declarator;
105   [[]] struct no_init_declarators; // expected-error {{an attribute list cannot appear here}}
106 }
107 [[]];
108 struct ctordtor {
109   [[]] ctordtor [[]] () [[]];
110   ctordtor (C) [[]];
111   [[]] ~ctordtor [[]] () [[]];
112 };
113 [[]] ctordtor::ctordtor [[]] () [[]] {}
114 [[]] ctordtor::ctordtor (C) [[]] try {} catch (...) {}
115 [[]] ctordtor::~ctordtor [[]] () [[]] {}
116 extern "C++" [[]] int extern_attr;
117 template <typename T> [[]] void template_attr ();
118 [[]] [[]] int [[]] [[]] multi_attr [[]] [[]];
119 
120 int comma_attr [[,]];
121 int scope_attr [[foo::]]; // expected-error {{expected identifier}}
122 int (paren_attr) [[]]; // expected-error {{an attribute list cannot appear here}}
123 unsigned [[]] int attr_in_decl_spec; // expected-error {{an attribute list cannot appear here}}
124 unsigned [[]] int [[]] const double_decl_spec = 0; // expected-error 2{{an attribute list cannot appear here}}
125 class foo {
126   void const_after_attr () [[]] const; // expected-error {{expected ';'}}
127 };
128 extern "C++" [[]] { } // expected-error {{an attribute list cannot appear here}}
129 [[]] template <typename T> void before_template_attr (); // expected-error {{an attribute list cannot appear here}}
130 [[]] namespace ns { int i; } // expected-error {{an attribute list cannot appear here}} expected-note {{declared here}}
131 [[]] static_assert(true, ""); //expected-error {{an attribute list cannot appear here}}
132 [[]] asm(""); // expected-error {{an attribute list cannot appear here}}
133 
134 [[]] using ns::i; // expected-error {{an attribute list cannot appear here}}
135 [[unknown]] using namespace ns; // expected-warning {{unknown attribute 'unknown' ignored}}
136 [[noreturn]] using namespace ns; // expected-error {{'noreturn' attribute only applies to functions}}
137 namespace [[]] ns2 {} // expected-warning {{attributes on a namespace declaration are a C++17 extension}}
138 
139 using [[]] alignas(4) [[]] ns::i; // expected-error {{an attribute list cannot appear here}}
140 using [[]] alignas(4) [[]] foobar = int; // expected-error {{an attribute list cannot appear here}} expected-error {{'alignas' attribute only applies to}}
141 
142 void bad_attributes_in_do_while() {
143   do {} while (
144       [[ns::i); // expected-error {{expected ']'}} \
145                 // expected-note {{to match this '['}} \
146                 // expected-error {{expected expression}}
147   do {} while (
148       [[a]b ns::i); // expected-error {{expected ']'}} \
149                     // expected-note {{to match this '['}} \
150                     // expected-error {{expected expression}}
151   do {} while (
152       [[ab]ab] ns::i); // expected-error {{an attribute list cannot appear here}}
153   do {} while ( // expected-note {{to match this '('}}
154       alignas(4 ns::i; // expected-note {{to match this '('}}
155 } // expected-error 2{{expected ')'}} expected-error {{expected expression}}
156 
157 [[]] using T = int; // expected-error {{an attribute list cannot appear here}}
158 using T [[]] = int; // ok
159 template<typename T> using U [[]] = T;
160 using ns::i [[]]; // expected-error {{an attribute list cannot appear here}}
161 using [[]] ns::i; // expected-error {{an attribute list cannot appear here}}
162 using T [[unknown]] = int; // expected-warning {{unknown attribute 'unknown' ignored}}
163 using T [[noreturn]] = int; // expected-error {{'noreturn' attribute only applies to functions}}
164 using V = int; // expected-note {{previous}}
165 using V [[gnu::vector_size(16)]] = int; // expected-error {{redefinition with different types}}
166 
167 auto trailing() -> [[]] const int; // expected-error {{an attribute list cannot appear here}}
168 auto trailing() -> const [[]] int; // expected-error {{an attribute list cannot appear here}}
169 auto trailing() -> const int [[]];
170 auto trailing_2() -> struct struct_attr [[]];
171 
172 namespace N {
173   struct S {};
174 };
175 template<typename> struct Template {};
176 
177 // FIXME: Improve this diagnostic
178 struct [[]] N::S s; // expected-error {{an attribute list cannot appear here}}
179 struct [[]] Template<int> t; // expected-error {{an attribute list cannot appear here}}
180 struct [[]] ::template Template<int> u; // expected-error {{an attribute list cannot appear here}}
181 template struct [[]] Template<char>; // expected-error {{an attribute list cannot appear here}}
182 template struct __attribute__((pure)) Template<std::size_t>; // We still allow GNU-style attributes here
183 template <> struct [[]] Template<void>;
184 
185 enum [[]] E1 {};
186 enum [[]] E2; // expected-error {{forbids forward references}}
187 enum [[]] E1;
188 enum [[]] E3 : int;
189 enum [[]] {
190   k_123 [[]] = 123 // expected-warning {{attributes on an enumerator declaration are a C++17 extension}}
191 };
192 enum [[]] E1 e; // expected-error {{an attribute list cannot appear here}}
193 enum [[]] class E4 { }; // expected-error {{an attribute list cannot appear here}}
194 enum struct [[]] E5;
195 
196 struct S {
197   friend int f [[]] (); // expected-FIXME{{an attribute list cannot appear here}}
198   friend int f1 [[noreturn]] (); //expected-error{{an attribute list cannot appear here}}
199   friend int f2 [[]] [[noreturn]] () {}
200   [[]] friend int g(); // expected-error{{an attribute list cannot appear here}}
201   [[]] friend int h() {
202   }
203   [[]] friend int f3(), f4(), f5(); // expected-error{{an attribute list cannot appear here}}
204   friend int f6 [[noreturn]] (), f7 [[noreturn]] (), f8 [[noreturn]] (); // expected-error3 {{an attribute list cannot appear here}}
205   friend class [[]] C; // expected-error{{an attribute list cannot appear here}}
206   [[]] friend class D; // expected-error{{an attribute list cannot appear here}}
207   [[]] friend int; // expected-error{{an attribute list cannot appear here}}
208 };
209 template<typename T> void tmpl(T) {}
210 template void tmpl [[]] (int); // expected-FIXME {{an attribute list cannot appear here}}
211 template [[]] void tmpl(char); // expected-error {{an attribute list cannot appear here}}
212 template void [[]] tmpl(short);
213 
214 // Argument tests
215 alignas int aligned_no_params; // expected-error {{expected '('}}
216 alignas(i) int aligned_nonconst; // expected-error {{'aligned' attribute requires integer constant}} expected-note {{read of non-const variable 'i'}}
217 
218 // Statement tests
219 void foo () {
220   [[]] ;
221   [[]] { }
222   [[]] if (0) { }
223   [[]] for (;;);
224   [[]] do {
225     [[]] continue;
226   } while (0);
227   [[]] while (0);
228 
229   [[]] switch (i) {
230     [[]] case 0:
231     [[]] default:
232       [[]] break;
233   }
234 
235   [[]] goto there;
236   [[]] there:
237 
238   [[]] try {
239   } [[]] catch (...) { // expected-error {{an attribute list cannot appear here}}
240   }
241   struct S { int arr[2]; } s;
242   (void)s.arr[ [] { return 0; }() ]; // expected-error {{C++11 only allows consecutive left square brackets when introducing an attribute}}
243   int n = __builtin_offsetof(S, arr[ [] { return 0; }() ]); // expected-error {{C++11 only allows consecutive left square brackets when introducing an attribute}}
244 
245   void bar [[noreturn]] ([[]] int i, [[]] int j);
246   using FuncType = void ([[]] int);
247   void baz([[]]...); // expected-error {{expected parameter declarator}}
248 
249   [[]] return;
250 }
251 
252 template<typename...Ts> void variadic() {
253   void bar [[noreturn...]] (); // expected-error {{attribute 'noreturn' cannot be used as an attribute pack}}
254 }
255 
256 // Expression tests
257 void bar () {
258   // FIXME: GCC accepts [[gnu::noreturn]] on a lambda, even though it appertains
259   // to the operator()'s type, and GCC does not otherwise accept attributes
260   // applied to types. Use that to test this.
261   [] () [[gnu::noreturn]] { return; } (); // expected-warning {{attribute 'noreturn' ignored}} FIXME-error {{should not return}}
262   [] () [[gnu::noreturn]] { throw; } (); // expected-warning {{attribute 'noreturn' ignored}}
263   new int[42][[]][5][[]]{};
264 }
265 
266 // Condition tests
267 void baz () {
268   if ([[unknown]] bool b = true) { // expected-warning {{unknown attribute 'unknown' ignored}}
269     switch ([[unknown]] int n { 42 }) { // expected-warning {{unknown attribute 'unknown' ignored}}
270     default:
271       for ([[unknown]] int n = 0; [[unknown]] char b = n < 5; ++b) { // expected-warning 2{{unknown attribute 'unknown' ignored}}
272       }
273     }
274   }
275   int x;
276   // An attribute can be applied to an expression-statement, such as the first
277   // statement in a for. But it can't be applied to a condition which is an
278   // expression.
279   for ([[]] x = 0; ; ) {} // expected-error {{an attribute list cannot appear here}}
280   for (; [[]] x < 5; ) {} // expected-error {{an attribute list cannot appear here}}
281   while ([[]] bool k { false }) {
282   }
283   while ([[]] true) { // expected-error {{an attribute list cannot appear here}}
284   }
285   do {
286   } while ([[]] false); // expected-error {{an attribute list cannot appear here}}
287 
288   for ([[unknown]] int n : { 1, 2, 3 }) { // expected-warning {{unknown attribute 'unknown' ignored}}
289   }
290 }
291 
292 enum class __attribute__((visibility("hidden"))) SecretKeepers {
293   one, /* rest are deprecated */ two, three
294 };
295 enum class [[]] EvenMoreSecrets {};
296 
297 namespace arguments {
298   void f[[gnu::format(printf, 1, 2)]](const char*, ...);
299   void g() [[unknown::foo(ignore arguments for unknown attributes, even with symbols!)]]; // expected-warning {{unknown attribute 'foo' ignored}}
300   [[deprecated("with argument")]] int i;
301   // expected-warning@-1 {{use of the 'deprecated' attribute is a C++14 extension}}
302 }
303 
304 // Forbid attributes on decl specifiers.
305 unsigned [[gnu::used]] static int [[gnu::unused]] v1; // expected-error {{'unused' attribute cannot be applied to types}} \
306            expected-error {{an attribute list cannot appear here}}
307 typedef [[gnu::used]] unsigned long [[gnu::unused]] v2; // expected-error {{'unused' attribute cannot be applied to types}} \
308           expected-error {{an attribute list cannot appear here}}
309 int [[carries_dependency]] foo(int [[carries_dependency]] x); // expected-error 2{{'carries_dependency' attribute cannot be applied to types}}
310 
311 // Forbid [[gnu::...]] attributes on declarator chunks.
312 int *[[gnu::unused]] v3; // expected-warning {{attribute 'unused' ignored}}
313 int v4[2][[gnu::unused]]; // expected-warning {{attribute 'unused' ignored}}
314 int v5()[[gnu::unused]]; // expected-warning {{attribute 'unused' ignored}}
315 
316 [[attribute_declaration]]; // expected-warning {{unknown attribute 'attribute_declaration' ignored}}
317 [[noreturn]]; // expected-error {{'noreturn' attribute only applies to functions}}
318 [[carries_dependency]]; // expected-error {{'carries_dependency' attribute only applies to parameters, Objective-C methods, and functions}}
319 
320 class A {
321   A([[gnu::unused]] int a);
322 };
323 A::A([[gnu::unused]] int a) {}
324 
325 namespace GccConst {
326   // GCC's tokenizer treats const and __const as the same token.
327   [[gnu::const]] int *f1();
328   [[gnu::__const]] int *f2();
329   [[gnu::__const__]] int *f3();
330   void f(const int *);
331   void g() { f(f1()); f(f2()); }
332   void h() { f(f3()); }
333 }
334 
335 namespace GccASan {
336   __attribute__((no_address_safety_analysis)) void f1();
337   __attribute__((no_sanitize_address)) void f2();
338   [[gnu::no_address_safety_analysis]] void f3();
339   [[gnu::no_sanitize_address]] void f4();
340 }
341 
342 namespace {
343   [[deprecated]] void bar();
344   // expected-warning@-1 {{use of the 'deprecated' attribute is a C++14 extension}}
345   [[deprecated("hello")]] void baz();
346   // expected-warning@-1 {{use of the 'deprecated' attribute is a C++14 extension}}
347   [[deprecated()]] void foo();
348   // expected-error@-1 {{parentheses must be omitted if 'deprecated' attribute's argument list is empty}}
349   [[gnu::deprecated()]] void quux();
350 }
351 
352 namespace {
353 [[ // expected-error {{expected ']'}}
354 #pragma pack(pop)
355 deprecated
356 ]] void bad();
357 }
358 
359 int fallthru(int n) {
360   switch (n) {
361   case 0:
362     n += 5;
363     [[fallthrough]]; // expected-warning {{use of the 'fallthrough' attribute is a C++17 extension}}
364   case 1:
365     n *= 2;
366     break;
367   }
368   return n;
369 }
370 
371 template<typename T> struct TemplateStruct {};
372 class FriendClassesWithAttributes {
373   // We allow GNU-style attributes here
374   template <class _Tp, class _Alloc> friend class __attribute__((__type_visibility__("default"))) vector;
375   template <class _Tp, class _Alloc> friend class __declspec(code_seg("foo,whatever")) vector2;
376   // But not C++11 ones
377   template <class _Tp, class _Alloc> friend class[[]] vector3;                                         // expected-error {{an attribute list cannot appear here}}
378   template <class _Tp, class _Alloc> friend class [[clang::__type_visibility__(("default"))]] vector4; // expected-error {{an attribute list cannot appear here}}
379 
380   // Also allowed
381   friend struct __attribute__((__type_visibility__("default"))) TemplateStruct<FriendClassesWithAttributes>;
382   friend struct __declspec(code_seg("foo,whatever")) TemplateStruct<FriendClassesWithAttributes>;
383   friend struct[[]] TemplateStruct<FriendClassesWithAttributes>;                                       // expected-error {{an attribute list cannot appear here}}
384   friend struct [[clang::__type_visibility__("default")]] TemplateStruct<FriendClassesWithAttributes>; // expected-error {{an attribute list cannot appear here}}
385 };
386 
387 #define attr_name bitand
388 #define attr_name_2(x) x
389 #define attr_name_3(x, y) x##y
390 [[attr_name, attr_name_2(bitor), attr_name_3(com, pl)]] int macro_attrs; // expected-warning {{unknown attribute 'compl' ignored}} \
391    expected-warning {{unknown attribute 'bitor' ignored}} \
392    expected-warning {{unknown attribute 'bitand' ignored}}
393 
394 // Check that we can parse an attribute in our vendor namespace.
395 [[clang::annotate("test")]] void annotate1();
396 [[_Clang::annotate("test")]] void annotate2();
397 // Note: __clang__ is a predefined macro, which is why _Clang is the
398 // prefered "protected" vendor namespace. We support __clang__ only for
399 // people expecting it to behave the same as __gnu__.
400 [[__clang__::annotate("test")]] void annotate3();  // expected-warning {{'__clang__' is a predefined macro name, not an attribute scope specifier; did you mean '_Clang' instead?}}
401