Re: sizeof(struct ...)

Erik Mouw schrieb:

On Thu, Nov 23, 2006 at 04:45:09PM +0100, René Scharfe wrote:

quoted

 Is there really a compiler that inserts padding between arrays of
unsigned chars?

Yes, that compiler is called "gcc".

#include <stdio.h>

struct foo {
        unsigned char a[3];
        unsigned char b[3];
};

int main(void)
{
        printf("%d\n", sizeof(struct foo));
        return 0;
}

On i386 that prints 6, on ARM it prints 8.

Does it add 1 byte after a and and 1 after b or two after b?
I suspect it's the latter case -- otherwise Gerrit's patch,
which started this thread, wouldn't help solve his problem.
Or the pad sizing follows complicated rules that I do not
understand at the moment.

Time to look for an ARM emulator, it seems.

Thanks,