[Bug c/32448] abs / printf bug

["rob1weld at aol dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #21 from rob1weld at aol dot com  2007-06-24 12:22 -------
(In reply to comment #20)
> > Since GCC can 'see' the "%f" at compile time
> ... that does not mean the behavior is the correct to cast it to float. ...

So the correct behavior is:

a): Cast it to something other than float.

 - if it can only be float (in the example, otherwise anything else) as far as 
   printf is concerned then why do that? I know you are NOT suggesting that we
   could cast it to (int) and use "%f" to print it and you are NOT suggesting
   that we could cast it to (char *), a string, and print it with "%f".

 - If the printf contains "%f" then the var "must" be a float.


Example:

  long double A = 123.456;
  int B = A;

Is the variable B an int, or something else. Why is it incorrect behaviour to
print it with %f even if that means we get (a compiler warning when compiling
and) 123.000 for output - would anyone prefer gibberish for output ?


b): do as I suggested and avoid the security issue, bad output, and the need
for contorted code (as shown in comment #18).


c): The Emperor's clothes look wonderful.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32448