Fix sprintf issue on MacOS for non-XCode compilers

[stephanlachnit]

@chriskohlhoff @klemens-morgenstern

This should fix the sprintf issue on MacOS for good, in particular if XCode is not used but e.g. clang from brew (see #1148 for discussion).

The issue is the check of ASIO_HAS_SNPRINTF here:

asio/asio/include/asio/detail/config.hpp

Lines 1411 to 1420 in 54e3a84

	// Standard library support for snprintf.
	#if !defined(ASIO_HAS_SNPRINTF)
	# if !defined(ASIO_DISABLE_SNPRINTF)
	# if defined(__apple_build_version__)
	# if (__clang_major__ >= 14)
	# define ASIO_HAS_SNPRINTF 1
	# endif // (__clang_major__ >= 14)
	# endif // defined(__apple_build_version__)
	# endif // !defined(ASIO_DISABLE_SNPRINTF)
	#endif // !defined(ASIO_HAS_SNPRINTF)

It only checks if __apple_build_version__ is defined, however this variable isn't set when using non-XCode compilers on MacOS. Since snprintf is available in MacOS since version 10.0, which was released in March 2001, is think the best option is to always set ASIO_HAS_SNPRINTF if __APPLE__ is detected.

Note that is also fixes a missing instance where sprintf_s can be used via Microsoft RTL.

Closes #1148 closes #1449 closes #1183

[stephanlachnit]

@chriskohlhoff can we get this merged? This is really annoying on MacOS with non-apple clang and a very simple fix.

[klemens-morgenstern]

Why can't you just define ASIO_HAS_SNPRINTF ?

[stephanlachnit]

Why can't you just define ASIO_HAS_SNPRINTF ?

Cause it is deprecated and the default should not emit a warning. And the Apple workaround only checks for Apple clang, while it should really check for the Apple C library, which is also used by upstream clang.