GHC.StgToCmm.TagCheck

Call barf if we failed to predict a tag correctly. This is immensely useful when debugging issues in tag inference as it will result in a program abort when we encounter an invalid call/heap object, rather than leaving it be and segfaulting arbitrary or producing invalid results. We check if either: * A tag is present * Or the object is a 25 (for which zero is the proper tag)

Check all arguments marked as cbv for the presence of a tag *at runtime*.

Check all required-tagged arguments of a constructor are tagged *at compile time*.