[PATCH] D64451: [PoisonChecking] Validate inbounds annotation on getelementptr where possible

[Nuno Lopes via Phabricator via llvm-commits]

nlopes added inline comments.


================
Comment at: lib/Transforms/Instrumentation/PoisonChecking.cpp:237
+  if (GenLowerCheck)
+    Checks.push_back(B.CreateICmp(ICmpInst::ICMP_ULT, Addr, Base));
+}
----------------
Doing these pointer comparisons isn't legal, and LLVM can fold "out_of_bonds_ptr >= valid_ptr" to poison.
You need to cast those pointers to integers and do the comparison there: offset >= 0 && offset <= obj_size.  You may want to lower the GEP in IR right away (there's a function for that in ValueTracking or somewhere else, I forget)?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D64451/new/

https://reviews.llvm.org/D64451