https://github.com/rjmccall commented:
So this is interesting, because I agree that the diagnostic message is misleading, but I'm not sure this is the right solution. The replaceable global `operator new` functions are required to return a pointer that's appropriately aligned to some target-specific value. In the user's test case, they're running on x86_64 Linux, where that value is 16. So they do actually have an invalid implementation of `operator new`. And I'm pretty sure we do in fact emit code and optimize based on the assumption that the pointer has this target-specific alignment, even if the allocated type has a lower alignment requirement than that. So this change — which IIUC actually changes UBSan to only check for the type's actual alignment — seems pretty problematic. Now, the diagnostic message is misleading because it's claiming that the type requires 16-byte alignment when it doesn't, but the narrow fix to that is to improve the diagnostic to talk about the requirements on global `operator new` when `allocationAlign` is greater than `allocAlign`, not to weaken the check. https://github.com/llvm/llvm-project/pull/152532 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
