[PATCH] D67122: [UBSan][clang][compiler-rt] Applying non-zero offset to nullptr is undefined behaviour

[Roman Lebedev via Phabricator via cfe-commits]

lebedev.ri added a comment.

In D67122#1656189 <https://reviews.llvm.org/D67122#1656189>, @aaron.ballman wrote:

> One fear I have with this is in expansions of the  `offsetof` macro, where it is a common implementation strategy to cast a null pointer to be of the correct type when calculating member offsets. Do you think you will be able to distinguish between null pointer additions that the user wrote directly (which is UB) as opposed to null pointer additions that come from the implementation (which is not UB)?


Can you show a snippet on godbolt?


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https://reviews.llvm.org/D67122