__attribute__ ((malloc)) semantics?

[Martin Dickopp <firefly-mail at gmx dot net>]

Hi,

I'm a bit confused what the effect of __attribute__ ((malloc)) is.
The GCC manual says:

    The `malloc' attribute is used to tell the compiler that a function
    may be treated as if it were the malloc function.  The compiler
    assumes that calls to malloc result in a pointers that cannot
    alias anything.  This will often improve optimization.

What does is mean to treat a function as if it were the malloc function,
other than assuming that the returned pointer does not alias anything?

E.g., would it be safe to use __attribute__ ((malloc)) on the following
function?

    int *foo (void) { static int i; return &i; }

Thanks,
Martin