[Bug c/56153] New: False warning about signed and unsigned type in conditional expression

[d.daniel at propharma dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56153



             Bug #: 56153

           Summary: False warning about signed and unsigned type in

                    conditional expression

    Classification: Unclassified

           Product: gcc

           Version: 4.6.3

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: c

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: d.dan...@propharma.ch





The following code creates a warning "signed and unsigned type in conditional

expression" but there is no such comparison:



typedef struct {

   unsigned int num;

   const char *str;

} FooBar;



FooBar *foo = (FooBar *)malloc (sizeof (FooBar));

foo->num = 0; 

foo->str = "Hello World";

fprintf (stdout, "%d", foo != 0 ? foo->num : -1);



If instead, the following code gets compiled, no warning is issued:



// .. the same as above

fprintf (stdout, "%d", foo != 0 ? foo->num : 1);