* Segher Boessenkool: > Let me quote the original mail (I had to dig it out of the archives as > well, no nice threading, too lazy, sorry): It still doesn't say why. I did see a reference to fleeting reference to <stdatomic.h> and <float.h>. My conjecture is that the real reason is avoid atomic emulation (softatomic?) and softfloat code. It's not related to <stdarg.h> at all: this header is replaced so that GCC's include subdirectory can be dropped from the include search path. What I don't know if this is to avoid obscure linker failures related to libatomic/softfloat (obviously not great) or run-time failures (worse). In any case, it would be nice to know what the real motivation is. After all, <stdatomic.h> is exactly like <stdarg.h> in that it's possible to use its functionality even without the header file. The __atomic builtins are even documented in the GCC manual (unlike <stdatomic.h>), which is why some programmers prefer them over the standard interface. And then there's the _Atomic keyword itself, whose use can easily result in calls to libatomic functions, too. So blocking <stdatomic.h> makes little sense to me. I don't know enough about softfloat if blocking the inclusion of <float.h> is worth it. Thanks, Florian
