| Issue |
149105
|
| Summary |
[clang] Semantics of `__attribute__((used))` differ from GCC
|
| Labels |
clang
|
| Assignees |
|
| Reporter |
can-leh-emmtrix
|
When using `__attribute__((used))` inside a template, its semantics differ between GCC and clang. The following test case outputs `test is called` when compiled with GCC and nothing when compiled with clang:
```cpp
#include <cstdio>
template <class T>
class C {
public:
static int test() {
puts("test is called");
return 0;
}
__attribute__((used))
static const int s1;
static void other_function() {}
};
template <class T>
const int C<T>::s1 = C<T>::test();
int main() {
C<int>::other_function();
return 0;
}
```
[Compiler Explorer Link](https://godbolt.org/z/e5dWxsbTe)
This also leads to different linking behaviour. While the following code links when compiled with clang, it does not when compiled with GCC:
```cpp
template <class T>
class C {
public:
static int test();
__attribute__((used))
static const int s1;
static void other_function() {}
};
template <class T>
const int C<T>::s1 = C<T>::test();
int main() {
C<int>::other_function();
return 0;
}
```
[Compiler Explorer Link](https://godbolt.org/z/KfGTfe6Yn)
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