On 10/5/06, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
On Thu, Oct 05, 2006 at 01:41:03AM -0700, Dan Carpenter wrote:
> Work on smatch is going ahead. I have one real life check is working
> and I've added a patched up the core code quite a bit.
For the mindless - can you please repeat what smatch does?
Sam
It's a static code checker. Take a look at check_null_deref.c.
You've got a function called match_assign() that gets called for every
assignment:
name = get_variable_from_expr(expr->left, &sym);
name = alloc_string(name);
if (is_null(expr->right))
set_state(name, my_id, sym, ISNULL);
else
set_state(name, my_id, sym, NONNULL);
Say it encounter the code: a = foo(), then it's going to set the
state of 'a' to NONNULL;
Then say it encounters a call to tty_ldisc_deref(), it's going to
check the state of 'a' and if it's ISNULL or UNDEFINED it's going to
print a message out.
More often you have something like:
a = NULL;
if (b) {
a = foo();
}
a->x; <---Error. 'a' is Undefined.
The idea is that it's easy to write checks once all the state tracking
code is in place.
Use it like this:
make C=1 CHECK=/path/to/smatch > warns.out 2>&1
regards,
dan carpenter
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