Jesse Ruderman Reporter
	Description • 12 years ago

A struct member might be useless if:

* It always has the same value (e.g. bug 851025).
* It is never read.
* It is only read immediately after being assigned.

and:

* The member isn't intentional padding for alignment.  (Not sure how these are usually marked -- maybe with a '_' prefix?)
* The struct is not seen being cast to another type.

	Nicholas Nethercote [inactive]
	Comment 1 • 12 years ago

clang's -Wunused-private-field (which is enabled by -Wall, and thus on in normal Mozilla builds) identifies private struct members that are never read, in at least some cases.  See bug 825105 for some examples.  I don't know exactly which cases it detects, and I couldn't find any documentation on that option.

	(no longer active)
	Comment 2 • 10 years ago

I think -Wunused-private-field is the best we can hope to achieve here.  We hit only a few of that warning right now, mostly in imported code.