gribozavr2 added a comment. > With this change, unions are modeled exactly as structs (as far as I can > tell), which is unsound.
Modeling just the storage of the union (but not the value) is sound. The first revision of the patch was a targeted fix that allowed us to continue maintaining the invariant that `this` is always modeled with a non-null `StorageLocation`. About modeling values of unions as structs (and members of unions as struct members), I can think of some unsoundness but nothing that affects what we are modeling now (e.g., pointers to two struct members should compare unequal, but pointers to two union members should compare equal). If the code writes to one union member, but reads from the other, code has UB. So it generally shouldn't be a problem, for the purpose of modeling, to model more storage in the union that a program free of union-related UB should never use. WDYT? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D140696/new/ https://reviews.llvm.org/D140696 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
