Messages in this thread | | | Date | Wed, 4 Oct 2006 12:43:10 -0700 | From | Andrew Morton <> | Subject | Re: Must check what? |
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On Wed, 4 Oct 2006 13:25:37 -0600 Matthew Wilcox <matthew@wil.cx> wrote:
> On Wed, Oct 04, 2006 at 12:02:42PM -0700, Andrew Morton wrote: > > I blame kernel-doc. It should have a slot for documenting the return value, > > but it doesn't, so nobody documents return values. > > There's also the question about where the documentation should go. By > the function prototype in the header? That's the easy place for people > using the function to find it. By the code? That's the place where it > stands the most chance (about 10%) of somebody bothering to update it > when they change the code.
yes, by the code, if it's C. In .h if it's C++.
> > It should have a slot for documenting caller-provided locking requirements > > too. And for permissible calling-contexts. They're all part of the > > caller-provided environment, and these two tend to be a heck of a lot more > > subtle than the function's formal arguments. > > Indeed. And reference count assumptions. It's almost like we want a > pre-condition assertion ...
We have might_sleep(), assert_spin_locked(), BUG_ON(!irqs_disabled()), etc.
I like assertions personally. If we had something like:
void foo(args) { locals;
assert_irqs_enabled(); assert_spin_locked(some_lock); assert_in_atomic(); assert_mutex_locked(some_mutex);
then we get documentation which is (optionally) checked at runtime - best of both worlds. Better than doing it in kernel-doc. Automatically self-updating (otherwise kernels go BUG).
But we'd need to sell the idea ;)
And we still need to document those return values in English.
(Or we do
return assert_zero_or_errno(ret);
which is a bit ug, but gets us there) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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