efriedma added a comment. > It's interesting to me that these array-bound checks don't seem to use > @llvm.objectsize in some form already.
That would be a cool experiment. That said, one of the upsides of the current ubsan is that whether it will produce a diagnostic is predictable (as long as you don't use uninitialized data); you lose that to some extent with llvm.objectsize because it depends on the optimizer. ================ Comment at: lib/CodeGen/CGExpr.cpp:833 + // Arrays don't have pass_object_size attributes, but if they have a constant + // size modifier it's the array size (C99 6.5.7.2p1). + if (auto *DecayedArrayTy = dyn_cast<DecayedType>(ParamDecl->getType())) ---------------- "int f(int a[10])" might look like an array, but it isn't: it's just a different syntax to declare a pointer. So it's legal to "lie" in the signature. (If you want to actually pass a pointer to an array, you have to write "int (*a)[10]".) And the definition of "static" says "an array with at least as many elements as specified by the size expression", which isn't a maximum, so that doesn't really help either. Most people would consider it bad style to put a number into the array bound which doesn't reflect reality, but I think we shouldn't try to check it unless the user explicitly requests it. https://reviews.llvm.org/D40940 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
