[Bug gcov-profile/110827] C++20 coroutines aren't being measured by gcov

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110827

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-07-27
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
                 CC|                            |iains at gcc dot gnu.org

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I'm seeing all code properly instrumented.  The coverage I see is

        -:    1:#include <coroutine>
        -:    2:#include <iostream>
        -:    3:
        -:    4:struct task {
        -:    5:  struct promise {
        -:    6:    using handle_t = std::coroutine_handle<promise>;
        1:    7:    task get_return_object() {
        1:    8:      return task{handle_t::from_promise(*this)};
        -:    9:    }
        1:   10:    std::suspend_never initial_suspend() noexcept { return {};
}
        1:   11:    std::suspend_always final_suspend() noexcept { return {}; }
    #####:   12:    void unhandled_exception() { std::terminate(); }
        1:   13:    void return_void() noexcept {}
        -:   14:    friend task;
        -:   15:  };
        -:   16:  using promise_type = promise;
        1:   17:  task(promise_type::handle_t handle) : handle_{handle} {}
        1:   18:  ~task() {
        1:   19:    if (handle_) {
        1:   20:      handle_.destroy();
        -:   21:    }
        1:   22:  }
        -:   23: private:
        -:   24:  promise_type::handle_t handle_;
        -:   25:};
        -:   26:
        1:   27:task foo() {
        -:   28:  std::cout << "Running..." << std::endl;
        -:   29:  co_return;
        2:   30:}
        -:   31:
        1:   32:int main(int argc, char **argv) {
        1:   33:  foo();
        1:   34:  return 0;
        -:   35:}

I have no idea why for example line 28 isn't marked executed.