va_arg with pointers
- by Yktula
I want to initialize a linked list with pointer arguments like so:
/*
* Initialize a linked list using variadic arguments
* Returns the number of structures initialized
*/
int init_structures(struct structure *first, ...)
{
struct structure *s;
unsigned int count = 0;
va_list va;
va_start(va, first);
for (s = first; s != NULL; s = va_arg(va, (struct structure *))) {
if ((s = malloc(sizeof(struct structure))) == NULL) {
perror("malloc");
exit(EXIT_FAILURE);
}
count++;
}
va_end(va);
return count;
}
The problem is that clang errors type name requires a specifier or qualifier at va_arg(va, (struct structure *)), and says that the type specifier defaults to int. It also notes instantiated form at (struct structure *) and struct structure *. This, what seems to be getting assigned to s is int (struct structure *).
It compiles fine when parentheses are removed from (struct structure *), but the structures that are supposed to be initialized are inaccessible.
Why is int assumed when parentheses are around the type argument passed to va_arg? How can I fix this?
