Does va_copy() require va_end()?

Question

When dealing with variable arguments, is it just va_start() that needs a matching va_end() call, or does va_copy() require a matching va_end() too, i.e

void foo(char *x, ...)
{
  va_list l,c;

  va_start(l,x);
  va_copy(c,l);

  ---
  va_end(c); //is this correct ?
  va_end(l);
}

Answer 1

Yes, every copy and the original, requires va_end() to be called. Your example is correct, the order of your va_end() calls can be reversed.

From ISO/IEC 9899:201x:

7.16.1.3 The va_end macro

The va_end macro facilitates a normal return from the function whose variable argument list was referred to by the expansion of the va_start macro, or the function containing the expansion of the va_copy macro, that initialized the va_list ap. The va_end macro may modify ap so that it is no longer usable (without being reinitialized by the va_start or va_copy macro). If there is no corresponding invocation of the va_start or va_copy macro, or if the va_end macro is not invoked before the return, the behavior is undefined.

The last sentence states that every va_start or va_copy must be accompanied by an va_end before returning.