https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127353
Bug ID: 127353
Summary: undefined reference to static variable found via
reflection
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ivan.lazaric.gcc at gmail dot com
Target Milestone: ---
Flags: "-std=c++26 -freflection"
```cpp
#include <meta>
template<typename>
struct storage {
static inline int value = 2;
};
consteval int& find_value(std::meta::info type) {
for (auto member : members_of(type, std::meta::access_context::unchecked()))
{
if (!has_identifier(member)) continue;
if (identifier_of(member) != "value") continue;
return extract<int&>(member);
}
throw;
}
int main() {
// equivalent to: return storage<int>::value;
return find_value(^^storage<int>);
}
```
Outcome:
```
/usr/bin/ld: /tmp/ccQokmqh.o: in function `main':
bug.cpp:(.text.startup+0x2): undefined reference to `storage<int>::value'
collect2: error: ld returned 1 exit status
```
Godbolt: https://godbolt.org/z/M6qaGjYT5
Noting two ways to get around this:
[[gnu::used]]: https://godbolt.org/z/hj5bq6b9P
different `find_value()` impl: https://godbolt.org/z/zjffbG4eG
