Re: {Spam?} Re: implicit cast from unsigned long to unsigned int gives no warning with -Wall (64 bits arch)

Vincent Torri <vtorri@xxxxxxxxxxxx> · Wed, 21 Nov 2007 21:08:29 +0100 (CET)

On Wed, 21 Nov 2007, Tom St Denis wrote:

Vincent Torri wrote:

hey,

I have an ubuntu 64 bits on my core 2 duo. gcc version is 4.1.2

I compile that code with -Wall:

unsigned int htonl (unsigned int i)
{
  i = 0;
  return 0;
}

int
main ()
{
  unsigned long i;
  unsigned int j;

  i = 0;
  j = htonl (i);

I want to know why you assume j = ... should give a warning but not i = 0. 
(hint: what is the type of 0?).

forget the j, it's htonl(i) that matters here. It's the only location 
where there is a implicit cast from a 64 bits int (i) to a 32 bits int 
(the parameter of htonl), like the subject is telling you.

Vincent Torri