[PATCH] D66664: [FIX] Nonnull is not always implied by dereferenceable

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

getPointerDereferenceableBytes returns some number of dereferenceable bytes.  If CanBeNull is true, that result is modified: if the pointer value is null, the number of known dereferenceable bytes is actually zero.

As far as I can tell, without your patch, the function implements this logic correctly, and the callers use the result correctly.  "CanBeNull == false" doesn't mean the pointer is non-null; it means the caller doesn't have to prove the value is non-null before using the "known dereferenceable bytes" result. The parameter CanBeNull should probably be named to clarify that, though; maybe "OrNull" would be better?


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https://reviews.llvm.org/D66664