What version of protobuf and what language are you using?

C++ with protobuf 24.2, installed via Homebrew

What operating system (Linux, Windows, ...) and version?

macOS 13.4.1

What runtime / compiler are you using (e.g., python version or gcc version)

$ clang --version
Apple clang version 14.0.3 (clang-1403.0.22.14.1)

What did you do?

Code that previously compiled with -Wall is now failing with:

/Users/danpat/test/example.pb.h:677:33: error: extra ';' inside a struct [-Werror,-Wextra-semi]
    PROTOBUF_TSAN_DECLARE_MEMBER;

It looks like the change was introduced with this commit:

33b8c45

When PROTOBUF_TSAN is not defined, PROTOBUF_TSAN_DECLARE_MEMBER is defined as empty, which leaves a standalone ; in the generated headers. This triggers a warning/error on Apple clang via the -Wextra-semi option, which is enabled as part of -Wall. I believe it would also trigger on newer GCC which also supports -Wextra-semi, but I'm not currently using any newer GCC versions and don't have a setup to test it.

What did you expect to see

My code still compiled after updating protobuf