On Thu, Nov 01, 2012 at 11:57:21AM -0700, Xinliang David Li wrote:
> That is exactly related to tsan -- it should skip local variable that
> is not address taken (though still addressable, which by addressable,
> it means the variable has a memory home).
>
> The problem is that if 'addressable' bit is not equivalent to 'address
> taken', it will be too conservative to use it --- as addressable
> variables may not be address taken.
But TREE_ADDRESSABLE is equivalent to address taken.
> Note that even 'address taken' is too conservative to use here. Only
> when it is escaped the thread (via non TLS global pointers or other
> escaped local, heap memories), should it be considered to be
> instrumented.
If you need it even less conservative, I guess you could do say:
struct ptr_info_def pi;
memset (&pi, 0, sizeof (pi));
pi.escaped = 1;
pi.nonlocal = 1;
return pt_solution_includes (&pi, decl);
(the nonlocal in pt_solution_includes_1 performs the is_global_var check
that needs to be done, and escaped checks whether decl is in the escaped
set).
Then say for
int foo(int i)
{
int a[100], b[100], c[100], d[100], *p;
if (i < 10)
p = a;
else if (i < 60)
p = b;
else if (i <= 65)
p = c;
else
p = d;
p[i] = 1;
p[2 * i] = 2;
return p[i + 1];
}
still none of a, b, c, and d vars will be included, even when they are
TREE_ADDRESSABLE, but if you say pass p to another function, or set a global
var to it, it will already return true for them.
Jakub
