https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98499
--- Comment #4 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Managed to shrink example even further. Now fails in `037t.fre1`:
```c++
struct string {
char * _M_buf;
// local store
char _M_local_buf[16];
__attribute__((noinline)) string() : _M_buf(_M_local_buf) {}
~string() {
if (_M_buf != _M_local_buf)
__builtin_trap();
}
string(const string &__str); // no copies
};
// main.cc
__attribute__((noinline)) static string dir_name() { return string(); }
class Importer {
string base_path;
public:
__attribute__((noinline)) Importer() : base_path (dir_name()) {}
};
int main() {
Importer imp;
}
```
```
$ g++-11.0.0 -O2 -std=c++11 main.cc -o a && ./a
Illegal instruction (core dumped) ./a
$ g++-11.0.0 --param=modref-max-depth=0 -O2 -std=c++11 main.cc -o a && ./a
<ok>
```
It feels like c++'s return-value-optimization somehow misses the PTA.
