rfc: __builtin_syntax_error

[Aldy Hernandez]

i need a builtin to trigger a syntax error for altivec.

something like this:

#define some_c_overloaded_fun(a)
  __builtin_choose_expr (__builtin_types_compatible (typeof(a), char),
			 something_char(a),
			 check for int.... something_int(a)
			 check for float.. something_float(a)
			 default: 
			   __builtin_syntax_error("invalid type", __LINE__)

is this something we could add generically-- or should i just make
an altivec only builtin?

thx
aldy