ABI for function call with big argument different than GCC (LLVM-54) #14
Description
I've noticed this while calling wifi_prov_mgr_init() that for some reason takes is argument by value, and its argument sizeof(wifi_prov_mgr_config_t) == 44.
But it can be seen with this simple code:
struct data {
int x[6];
};
void foo(struct data a) {
for (int i = 0; i < sizeof(a) / sizeof(a.x[0]); ++i)
printf("%2d: %d\n", i, a.x[i]);
}
If I compile this code with CLang and call it from CLang, all is well. But if I compile it with GCC and call it from CLang, it prints garbage values.
If I reduce the x[6] to x[4] it works as expected.
But if I change the int x[4] to char x[4] it breaks in a different way, as if there were padding bytes between the elements of the array.