https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98861
--- Comment #25 from cqwrteur <unlvsur at live dot com> --- > > 1. Freestanding C++ in the current situation is very problematic. (You do > > not have memcpy, you do not have std::move. You do not have std::forward. > > You do not have std::addressof(). you do not have std::array.) However, you > > have an exception handling support. > > But no dependency on stdio. That does not mean it has no dependency. It depends on malloc/free which is something you cannot avoid at all. BTW, there are other issues with the implementation EH unwinder, it walks stack twice for just more debugging information. Guess what is the information consumed for? They output to stdio lol. Your termination with multiple fputs calls also has issues even in a hosted environment. Because it is not process-safe. When multiple processes throw eh at the same time, they end up corrupting log files. (I did see that when i was doing testing on the burden of multiple process TCP servers.) I guess changing that to writev(2) might solve part of the problems but writev(2) does not guarantee process safety for console or other I/O devices. > > > 2. What's the point of reporting a bug when building libstdc++ with GNU > > So it can be fixed, duh. > > > newlib just works much better and you have an entire hosted toolchain that > > will not break compilation? The only problem is that you never enable EH. > > I did report bugs before. However, it was not fixed. I am not going to try > > it again tbh since newlib works just fine. > > Great. So build with --disable-libstdcxx-verbose as well and stop > complaining about a feature that other people find useful. > > Maybe we should make that the default for --with-newlib builds. That might > be a useful improvement. More useful than your usual hyperbole and > timewasting anyway. I mean you can try to fix it a little. However, it breaks ABI. The effort does not worth the cost. More fundamental issues like binary bloat would never get fixed. Unfortunately, the C++ compiler does not remove dead virtual functions. The entire C++ exceptions are built on virtual function calls. That stuff all add bloat you do not want. Recently I just remove one virtual method of EH and the binary size reduces 50KB for hello world. If the exceptions are just designed for termination, it is nowhere better than killing the process and restarted it again. (With __builtin_trap() you even get higher performance than EH in the happy path because it reduces the burden of CPU instruction cache) For servers hosted on the internet, using EH is a disaster since it is basically DDOS. The attacker can inject invalid input to make the process keep throwing EH which ends up crashing. (There are security papers talking about that. I can even show you). EH does not work for cryptography either since cryptography requires deterministic. Any gap between timing can be a side-channel.
