https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103949
--- Comment #8 from Jörn Heusipp <manx-bugzilla at problemloesungsmaschine dot de> --- > Note in newer versions of glibc, libpthread is all intergrated into libc and > there is no issues again. > > For Mac OS X/darwin you don't need -lm -pthread because libc has it. Two examples where it works by chance is not sufficient to invalidate my point about the general case. > >gcc libstdc++ implements std::thread. So what's your point again? > > Because it implements it on top of pthreads. Yeah, so that is an implementation detail because of which I am required to pass -pthread. Why should the user of gcc even care how std::thread is implemented? It literally makes no sense. You are supporting my point. > While C threads is implemented > inside the libc. If it was implemented in libc, I would not be seeing "c11.c:(.text+0x53): undefined reference to `thrd_create'". Something is wrong with your argument. I actually do not know where it is implemented. And I should not be needing to know. Again, you are supporting my point. > If you want __STDC_NO_THREADS defined file a bug about that but gcc will need > to record which versions of glibc has C11 thread defined or not. The compiler is required to know that by the C standard. > You could use __has_include extension which will handle that mostly for you > really. That's not how the C standard specifies to do to check for thread support. > I still think this should not be done on the GCC side as it is > changing/fixing on the glibc side of things already. There are more platforms that GCC targets than just glibc. glibc alone cannot fix the general case. > In the case of mingw, the problem is how GCC was configured: Debian MinGW-w64 gcc is built in 2 flavours. One with Win32 and one with posix threading model support. The version with posix threading model support uses pthreads, and knows how to implement std::thread. Why is GCC assuming single-threaded in that context? That seems like a broken configuration to me that gcc should not allow to be buildable, which looks like a bug to me. (or I am misunderstanding what you are saying)
