(printf) ("hello world\n");

[Robert Dewar]

Andreas Schwab wrote:

> Eyal Lebedinsky <eyal@eyal.emu.id.au> writes:
> 
> 
>>But without <stdio.h> the varargs attribute is not present
> 
> 
> A varargs function is always a varargs function, whether it is prototyped
> or not.  But without a proper prototype the behaviour is undefined.

Is it really true that the name printf is reserved? Is a C program not
allowed to define its own printf function (which might or might not be
varargs)? What's the story here?