Messages in this thread | | | Date | Thu, 2 Aug 2007 13:05:15 +0100 | From | Al Viro <> | Subject | Re: [RFC PATCH] type safe allocator |
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On Thu, Aug 02, 2007 at 09:27:57AM +0200, Miklos Szeredi wrote: > > Quite frankly, I suspect you would be better off just instrumenting > > "sparse" instead, and matching up the size of the allocation with the type > > it gets assigned to. > > But that just can't be done, because kmalloc() doesn't tell us the > _intent_ of the allocation.
Of course it can be done. When argument has form sizeof(...), attach the information about target of pointer to the resulting void *; have ? : between pointer to object and that one warn if types do not match, ? : between void * and that one lose that information, ? : between two such warn when types do not match. On assigment-type operations (assignment, passing argument to function, initializer, return) when the type of target is pointer to object (and not void *) warn if types do not match. Have typeof lose that information.
Not even hard to implement; just let us finish cleaning the lazy examination logics up first (~5-6 patches away).
FWIW, I object against the original proposal, no matter how you name it. Reason: we are introducing more magical constructs that have to be known to human reader in order to parse the damn code.
Folks, this is serious. _We_ might be used to having in effect a C dialect with extensions implemented by preprocessor. That's fine, but for a fresh reader it becomes a problem; sure, they can dig in include/linux/*.h and to some extent they clearly have to. However, it doesn't come for free and we really ought to keep that in mind - amount of local idioms (and anything that doesn't look like a normal function call with normal arguments _does_ become an idiom to be learnt before one can fluently RTFS) is a thing to watch out for.
IOW, whenever we add to that pile we ought to look hard at whether it's worth the trouble. - 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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