Can Whirlwind Attack be used with Great Cleave?

Question

In this related answer a combo is mentioned that involves using Great Cleave and Whirlwind Attack together to get extra attacks from cleave by killing things with whirlwind attack.

However I do not see how this could work since Whirlwind Attack specifies that:

When you use the Whirlwind Attack feat, you also forfeit any bonus or extra attacks granted by other feats, spells, or abilities.

Was this combo just a thought experiment that did not actually work by RAW or am I missing something in this interaction?

Answer 1

Not since the 3.5 revision

That's the post 3.5 revision of the feat Whirlwind Attack (Player's Handbook (2003) 102). The original 3e version of the feat (that can be found with some searching here) lacked that warning and had this benefit:

When the character performs the full attack action, he or she can give up all regular attacks and instead make one melee attack at the full base attack bonus against each opponent within 5 feet. (Player's Handbook (2000) 86)

Thus the original feat's benefit tacitly encouraged hauling around a bag of rats to facilitate many, many attacks against the big bad by those PCs who also possessed the feat Great Cleave.

While the feat goes unmentioned in the Revision Spotlight Web column (consolidated here), as a reader of the Wizards of the Coast forums during the pre- and post-revision process, many assume—as do I—that the changes made by the revision to the Whirlwind Attack feat were a direct response to the Bag of Rats Issue.

Answer 2

You can make a case for it

The argument basically goes that the forfeit is a one-time thing: you forfeit any extra attacks you had at the time. Great Cleave grants extra attacks after this point: when you forfeited them, you didn’t have them to lose, and now that you have them, the forfeiture is already a done thing.

Considering how absolutely atrocious the Whirlwind Attack and Great Cleave feats are, and how non-trivial a bag of rats actually is (to say nothing of setting up such a situation without something as abusive as a bag of rats), this isn’t really that unreasonable from my perspective, but YMMV on whether or not you buy it’s what the authors meant.

It doesn’t ultimately matter, because plenty of definitely-real options exist

In the context where this was raised, it doesn’t really matter whether or not you buy that particular combo: plenty of other combos are more unambiguously functional in similar situations. I take the other answer at its word that this particular combo was the origin of the term, which justifies highlighting it even if it arguably doesn’t work.