rnk added inline comments.
================ Comment at: clang/lib/AST/RecordLayoutBuilder.cpp:1890 - bool FieldPacked = Packed || D->hasAttr<PackedAttr>(); + llvm::Triple Target = Context.getTargetInfo().getTriple(); + bool FieldPacked = (Packed && (!FieldClass || FieldClass->isPOD() || ---------------- I think GCC implements this by ignoring the packed attribute on classes with such non-C++98-pod fields. See this case for example: https://gcc.godbolt.org/z/fe8x1ne7o ``` class NonPod { void method(); int x; }; struct __attribute__((packed)) PackedNonPod { char a; NonPod b; char c; int d; }; PackedNonPod gv; static_assert(sizeof(PackedNonPod) == 4 * 4, "drop packed"); ``` --> ``` <source>:7:12: warning: ignoring packed attribute because of unpacked non-POD field 'NonPod PackedNonPod::b' 7 | NonPod b; ``` So, in this case, the entire record is unpacked. `d` appears at offset 12, and the overall size is 16. Your code, as I understand it, handles each field individually, which isn't quite the same. I think the fix is in Sema somewhere to drop the attribute. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D117616/new/ https://reviews.llvm.org/D117616 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
