🚀 go-pugleaf

In article <17tieoINNsr5@news.aero.org> strauss@Aero.org (Daryll Strauss) writes:
>In article <1992Aug28.190230.2670@next.cambridge.ma.us>, simsong (Simson L. Garfinkel) writes:
>|> Apparently, when you include the -ObjC flag, all stack variables are  
>|> initialized to 0.
>|> 
>
>It would be a really bad idea to rely on that "feature." You must clear
>the sockaddr structure to use it. The C spec says that stack variables
>have unknown values. I've need heard anything different in for ObjC. So
>relying on the compiler to initialize variables for you is a disaster
>waiting to happen.

It's especially a bad idea seeing as how it's plain out
untrue!  The ObjC flag to the linker DOES NOT clear stack
variables to 0.  When you pass ObjC to the linker, it pulls
in a bunch of support for ObjC.  Because of this, in an
itsy-bitsy tiny example program like the one posted, a
large portion of the stack will end up filled with 0
values.   


But this will only remain true for the first function
call.  To see what I mean, change the program a bit: 

int     foo(n)
{
        int     a,b;
        int     c;

        printf("a=%d  b=%d  c=%d\n",a,b,c);
        a = n;
        c = n;
}

main()
{
        int a,b,c;

	foo(17);
	foo(13);
	foo(11);
	foo(7);
	foo(5);
	foo(3);
	foo(2);
	foo(1);
}

The sample program and output that Simson Garfinkel
posted works by mere coincidence.