Re: [Qemu-devel] [PATCH] use qemu_malloc and friends consistently

[David Turner <digit@google.com>]

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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
>

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