[Tinycc-devel] __builtin_va_* builtins missing

[Daniel Wingerd]

I'm working on getting musl to build using TCC and the first problem I
encountered was that TCC is missing __builtin_va_* builtins.  I've
tried adding it on my own and failed miserably since I don't really
understand TCC's internals.  I do recognize the va_* macros are
defined in include/stdarg.h but all the C compilers I've checked (even
Watcom and PCC) define these as builtin functions so it only seems
right that TCC follow suit instead of expecting special exceptions to
be made for it (in every libc's stdarg.h).

Explicitly, these need to be added into tcctok.h and implemented in
tccgen.c in the unary() function.
__builtin_va_start
__builtin_va_arg
__builtin_va_copy
__builtin_va_end

It shouldn't be a much effort for someone who knows the TCC internals
since their behavior is clearly defined in TCC's include/stdarg.h.

Is anyone willing to take up this task?

- Daniel