| // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -verify -std=c++11 %s |
| |
| static int test0 __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}} |
| static void test1() __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}} |
| |
| namespace test2 __attribute__((weak)) { // expected-warning {{'weak' attribute only applies to variables, functions, and classes}} |
| } |
| |
| namespace { |
| int test3 __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}} |
| void test4() __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}} |
| } |
| |
| struct Test5 { |
| static void test5() __attribute__((weak)); // no error |
| }; |
| |
| namespace { |
| struct Test6 { |
| static void test6() __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}} |
| }; |
| } |
| |
| // GCC rejects the instantiation with the internal type, but some existing |
| // code expects it. It is also not that different from giving hidden visibility |
| // to parts of a template that have explicit default visibility, so we accept |
| // this. |
| template <class T> struct Test7 { |
| void test7() __attribute__((weak)) {} |
| static int var __attribute__((weak)); |
| }; |
| template <class T> |
| int Test7<T>::var; |
| namespace { class Internal {}; } |
| template struct Test7<Internal>; |
| template struct Test7<int>; |
| |
| class __attribute__((weak)) Test8 {}; // OK |
| |
| __attribute__((weak)) auto Test9 = Internal(); // expected-error {{weak declaration cannot have internal linkage}} |
| |
| [[gnu::weak]] void weak_function(); |
| struct WithWeakMember { |
| [[gnu::weak]] void weak_method(); |
| [[gnu::weak]] virtual void virtual_weak_method(); |
| }; |
| constexpr bool weak_function_is_non_null = &weak_function != nullptr; // expected-error {{must be initialized by a constant expression}} |
| // expected-note@-1 {{comparison against address of weak declaration '&weak_function' can only be performed at runtime}} |
| constexpr bool weak_method_is_non_null = &WithWeakMember::weak_method != nullptr; // expected-error {{must be initialized by a constant expression}} |
| // expected-note@-1 {{comparison against pointer to weak member 'WithWeakMember::weak_method' can only be performed at runtime}} |
| // GCC accepts this and says the result is always non-null. That's consistent |
| // with the ABI rules for member pointers, but seems unprincipled, so we do not |
| // follow it for now. |
| // TODO: Consider warning on such comparisons, as they do not test whether the |
| // virtual member function is present. |
| constexpr bool virtual_weak_method_is_non_null = &WithWeakMember::virtual_weak_method != nullptr; // expected-error {{must be initialized by a constant expression}} |
| // expected-note@-1 {{comparison against pointer to weak member 'WithWeakMember::virtual_weak_method' can only be performed at runtime}} |