[avr-gcc-list] are signed chars signed :-) ?

[Bernard Fouché]

Hi there.

If I write the following code, the compiler (3.4.1) is happy:

void f(void)
{
        char a;

        a=-3;
        if(a>0)
                printf("Hello\n");
}

However if I change the test to:

        if(a>=0)
                printf("Hello\n");

then the compiler complains :

file.c:<line number>: warning: comparison is always true to limited range of
data type.

I just do not understand why I get such a warning! Gcc 3.3.2.1 on Linux
groks the function without complaining with -Wall. 'a' being signed, I feel
I have the right to compare it to being greater or equals to zero, no ? ;-)

I looked at http://gcc.gnu.org/bugzilla with the string 'avr', found 5 bugs
currently opened, went thru the old bugs and found nothing.. I must be
missing something obvious! (time to go to sleep ? :-))