function_hooks: fake an assignment when functions return "0-s32max[$0->bar]"
Say a function returns a parameter or a member of a parameter like this:
struct my_type *get_bar(struct foo *foo)
{
return foo->bar;
}
Then we can create a fake assignment for the caller: my_bar = foo->bar;
The reason I didn't do this before was that it was a bit complicated to
take a string and generate an expression. It turns out that when you
call a function, then you've already got most of the expression, you just
need to add the "->bar" part which isn't so hard.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>