dtcxzyw wrote: > this check needs to happen at a higher level. And at that level, you should > have an Expr*, not just an Address.
I tried to use `Expr::isNullPointerConstant` in `CodeGenFunction::EmitMemberExpr`: https://github.com/llvm/llvm-project/blob/59fd2878fce470f02058f43d4b818ed68ce04094/clang/lib/CodeGen/CGExpr.cpp#L4774-L4781 ``` struct S { int x, y; }; using uintptr_t = unsigned long long; uintptr_t get_offset_of_y_naively() { return ((uintptr_t)(&(((S *)nullptr)->y))); } ``` The base expr is: ``` ParenExpr 0x58d207ad2048 'S *' `-CStyleCastExpr 0x58d207ad2020 'S *' <NoOp> `-ImplicitCastExpr 0x58d207ad2008 'S *' <NullToPointer> part_of_explicit_cast `-CXXNullPtrLiteralExpr 0x58d207ad1f80 'nullptr_t' ``` `isNullPointerConstant` returns false regardless of the value of NullPointerConstantValueDependence. > Do you care at all about patterns like ((uintptr_t)(&(((S *)nullptr)->y.z)));? Yes. This pattern is used by openssl. https://github.com/llvm/llvm-project/pull/130734 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
