On Tue, Jun 2, 2009 at 10:04 PM, Paul Brook <paul@codesourcery.com> wrote:

My point is that

#define QEMU_NEW(type) ((type *)qemu_malloc(sizeof(type)))
foo *ptr = QEMU_NEW(foo);

is just as safe as

#define QEMU_NEW(ptr) (ptr) = qemu_malloc(sizeof(*(ptr)))
foo *ptr;
QEMU_NEW(ptr);

Because the compiler will catch the type mismatch.

I still don't see the point.
There is no type mismatch in the first version since the C standard mandates that a (void*) *must* be silently casted into any other typed pointer (unlike C++ which forbids this).

I think you're afraid of the following case instead:

foo* ptr;
ptr = QEMU_MEW(bar); => compiler will complain that 'ptr' is not a bar*

But this is not possible with the first version anyway.

Paul