MinGW maps the "printf" format string archetype to the non-standard
MSVCRT functions, even if __USE_MINGW_ANSI_STDIO is defined and set
to 1. We need to use "gnu_printf" to use the format strings as provided
by vsnprintf and similar functions to get correct warnings.
Since "gnu_printf" isn't necessarily available on other GCC compatible
compilers (such as clang), do this only on MinGW.
The destructors used by talloc take a "void *" first parameter.
However talloc.h had a #define hack that treated the destructor as a
function taking first parameter of type "typeof(ptr)" where ptr is the
pointer the destructor is set for. I suppose this was done to add some
kind of "type safety" against adding a destructor expecting another
type of pointer; however this hack is questionable and violates the
real C level typing. Remove the hack from the header and adjust
talloc.c to avoid a warning about a C type violation that became
visible after removing the hack.
libsmbclient uses dynamically linked libtalloc.so which has symbols
with names matching those in the internal talloc.c. This name
collision caused a crash under stream_smb when trying to play
anything with smb://. Add a "#pragma GCC visibility" hack to talloc.h
to hide the internal symbols from being visible to the outside
libtalloc.so. Hopefully this doesn't break any platform worse than
possibly causing a compiler warning about an unknown pragma (at least
GCC and clang recognize it).
