RFC: function parm attribute: must_assign

[jbbachky at aim dot com]

After upgrading to gcc-4.2.1 from a 3.4 version, I see that gcc now 
complains about uninitialized variables even when their address is 
passed to another function. Now that we get a warning about that 
variable being possibly initialized, I'm forced to add an instruction 
or two to initialize it (after I determine an appropriate value) or 
declare the function like this:

foo( __attribute__((must_assign)) long *ptr);
{
*ptr = _base_address_;
}

bar()
{
int *p;
foo( &p);

*p = ...
}
There's two things I really like about this:
1) In the caller, my warning goes away without having to determine an 
appropriate value in each caller of foo
2) In the callee, gcc can give a warning if there are any paths which 
leave that parm uninitialized.

If there's some other mechanism to achieve this functionality, I'd be 
interested in hearing about it. And if this is a new idea, I offer it 
to the gcc community.
John