[Bug c/42005] New: too many expressions recognised as null pointer constants?

[michael dot norrish at gmail dot com]

The following code prompts a warning on the line f(n - 1), but not on the line
f(n - n).  I guess this is because n - n is being turned into zero too early. 
(Definition of null pointer constant says it must be a constant expression; n -
n is not one.)

void g(int n)
{
  void f(int *);
  f(n - 1);
  f(n - n);
}


-- 
           Summary: too many expressions recognised as null pointer
                    constants?
           Product: gcc
           Version: 4.3.3
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: michael dot norrish at gmail dot com
  GCC host triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42005