[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 inline comments.


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Comment at: llvm/docs/ReleaseNotes.rst:59
+  ``getelementptr inbounds`` can not change the null status of a pointer,
+  meaning it can not produce non-null pointer given null base pointer, and
+  likewise given non-null base pointer it can not produce null pointer; if it
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xbolva00 wrote:
> lebedev.ri wrote:
> > xbolva00 wrote:
> > > Please add a reference to C/C++ standard that this is a UB.
> > It is irrelevant what semantics C/C++ standard has/doesn't have for whatever C/C++ construct,
> > this is talking about LLVM IR.
> Ok, so Clang docs?
> 
> “The compiler now optimizes ... since ... is a UB according to ... Use UBSan to catch these cases.”
... see `clang/docs/ReleaseNotes.rst` then?
Those words were present in the first revision of the differential already,
https://reviews.llvm.org/D67122?id=218504#change-RNUd6wICb9iD


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  https://reviews.llvm.org/D67122/new/

https://reviews.llvm.org/D67122