http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52534
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-15 10:03:59 UTC --- Because otherwise void foo (char a, ...) { __builtin_va_list va; __builtin_va_start (va, a); __builtin_va_end (va); } would not work (arg there is (int) a, as char is promoted to int). IMHO if we want to diagnose this, it should be done in the C/C++ FEs, e.g. for C FE perhaps in c_parser_postfix_expression_after_primary, by requiring that the second argument to __builtin_va_start is an identifier token, rathern than a + 0 or similar.