NoQ added a comment. That was fast! Looks alright.
================ Comment at: clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp:25 public: void checkPreStmt(const CXXNewExpr *NE, CheckerContext &C) const; ---------------- Before i forget: Ideally @martong should have subscribed to [[ https://clang.llvm.org/doxygen/classclang_1_1ento_1_1CheckerDocumentation.html#a7fdb3b5ff726f4c5e782cef0d59c01ad | `checkNewAllocator` ]] because it fires before the construct-expression whereas this callback fires after construct-expression which is too late as the UB we're trying to catch has occured much earlier. ================ Comment at: clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp:165-166 + if (const MemRegion *MRegion = PlaceVal.getAsRegion()) { + if (const FieldRegion *TheFieldRegion = MRegion->getAs<FieldRegion>()) + MRegion = TheFieldRegion->getBaseRegion(); + ---------------- You're saying that `A` is a struct and `a` is of type `A` and `&a` is sufficiently aligned then for //every// field `f` in the struct `&a.f` is sufficiently aligned. I'm not sure it's actually the case. ================ Comment at: clang/lib/StaticAnalyzer/Checkers/CheckPlacementNew.cpp:196-197 + } + } else if (Optional<loc::ConcreteInt> TheConcreteInt = + PlaceVal.getAs<loc::ConcreteInt>()) { + uint64_t PlaceAlign = *TheConcreteInt.getValue().getValue().getRawData(); ---------------- I don't think you'll ever see this case in a real-world program. Even if you would, i doubt we'll behave as expected, because we have [[ https://github.com/llvm/llvm-project/blob/llvmorg-10.0.0/clang/lib/StaticAnalyzer/Core/Store.cpp#L456 | certain hacks ]] in place that mess up arithmetic on concrete pointers. I appreciate your thinking but i suggest removing this section for now as it'll probably cause more false positives than true positives. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D76996/new/ https://reviews.llvm.org/D76996 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
