[Bug c/30729] New: [4.1/4.2/4.3 Regression] value computed is not used warning with unused result of va_arg

[pinskia at gcc dot gnu dot org]

#include <stdarg.h>

int f(int t, ...)
{
  va_list a;
  va_start (a, t);
  va_arg(a, int);
  int t1 = va_arg(a, int);
  va_end(a);
  return t1;
}


-----
We get a warning on the line which just contains va_arg(a, int);
Even though the value is not used, a is still incremented so the result is not
unused after all.

t.c:7: warning: value computed is not used


-- 
           Summary: [4.1/4.2/4.3 Regression] value computed is not used
                    warning with unused result of va_arg
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30729