Upgrade using fmt library up to latest version

[Saigut]

I tried fmt 3.0.0, 3.0.2, and 8.0.1, all failed to compiled.

[saurik]

soralog requires a version of fmt before fmtlib/fmt@841aad9, which removed the fmt_internal::data::reset_color that soralog is awkwardly relying on in sink_to_console.cpp; using git describe --tags, I think that means 7.1.3 is OK (if you want a release)?

soralog/src/impl/sink_to_console.cpp

Line 65 in 6184419

const auto &style = fmt_internal::data::reset_color;

However, I'll also note that fmt broke on iOS between fmtlib/fmt@15c10b0 and fmtlib/fmt@69bdc20 due to fmtlib/fmt#2248 (which I had actually filed), and so I actually use fmtlib/fmt@308510e for soralog (which is depressing, as it is now a year old).

[Saigut]

I am using fmt-7.1.2, which works well. And I have not tried 7.1.3.

[xDimon]

Sorry for delay.
Now fmt version 6.1.2 is used. It is default version in current using hunter package manager.
You might try to use other version by modifying Hunter/config.cmake. It will override default version from hunter.

hunter_config(
    fmt
    URL https://github.com/..../archive.tar.gz
    SHA1 hash-of-provided-archive
)

[saurik]

@xDimon FWIW, if you stop using that one variable from fmt_internal (which I would imagine projects aren't "supposed" to be using at all) we can all upgrade to the latest version of fmt. (I am definitely not building with Hunter, btw: it seems to be riddled with ancient versions of packages? I always do a build system bypass of imported libraries so I can correctly manage all the dependencies and do what I can to force them to master. I might try adding a hack to just disable color or whatever soralog is needing this for so I can make sure to be on the latest fmt code.)

[xDimon]

Any hacks is bad way. I'll try to switch to last version of fmt (8.1.1) for next version soralog.

[xDimon]

Oh, it was really easy. =)
@Saigut @saurik, look at soralog v0.1.1. I hope it is so what you needed.

[Saigut]

@xDimon That looks good :)
In fact I don't care if fmt is the newest version. The real problem for me is that I don't know the dependencies of soralog.
I am not using Hunter package manager in my own project. I have trouble to look out what version packages soralog is depending on when I first time look at soralog.

[saurik]

@xDimon Thanks!! This did, in fact, allow me to upgrade to a much newer version of fmt :D.

That said, I'm now ("still"? I feel like I didn't have this before, though? I'm confused a bit ;P) running into two issues preventing me from fully upgrading fmt, but I don't know if these issues are in soralog itself or are in the library that I'm compiling (cpp-libp2p) which is using soralog. Maybe you'd be willing to comment? (I'd appreciate if you don't want to, but the reason I ask is because the code using soralog naively looks reasonable to me and the issues both happen on the "other side" of soralog and seem to be fixable in soralog.)

---

1. In fmtlib/fmt@4b8bda2 from Aug 23 2021, fmt replaced a const reference with a forwarding reference in the definition of forward_to_n, supposedly as a fix for Should format_to_n has the same detection as format and format_to? fmtlib/fmt#2462; and then in cpp-libp2p, there is a use of SL_DEBUG that is triggering a static_assert in fmt "detail::count() == 0" "passing views as lvalues is disallowed" when soralog attempts to call fmt::v8::basic_format_string.

https://github.com/libp2p/cpp-libp2p/blob/890b53dd73452a555a5c7feaa9f73c5bdca1a9af/src/protocol_muxer/multiselect/multiselect_instance.cpp#L347-L348

      SL_DEBUG(log(), "Failed to negotiate protocols: {}",
               fmt::join(protocols_.begin(), protocols_.end(), ", "));

In file included from cpp-libp2p/src/protocol_muxer/multiselect/multiselect_instance.cpp:11:
In file included from ./cpp-libp2p/include/libp2p/common/trace.hpp:9:
In file included from ./cpp-libp2p/include/libp2p/log/logger.hpp:10:
In file included from ./soralog/include/soralog/logger.hpp:13:
In file included from ./soralog/include/soralog/sink.hpp:14:
In file included from ./soralog/include/soralog/event.hpp:14:
In file included from ./p2p/fmt/include/fmt/format.h:49:
./p2p/fmt/include/fmt/core.h:3067:5: error: static_assert failed due to requirement 'detail::count() == 0' "passing views as lvalues is disallowed"
    static_assert(
    ^
./soralog/include/soralog/event.hpp:62:65: note: in instantiation of function template specialization 'fmt::v8::basic_format_string<char, const fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char> &>::basic_format_string<FMT_COMPILE_STRING, 0>' requested here
            fmt::format_to_n(message_data_, max_message_length, format, args...)
                                                                ^
./soralog/include/soralog/circular_buffer.hpp:41:28: note: in instantiation of function template specialization 'soralog::Event::Event<soralog::Sink::ThreadInfoType, FMT_COMPILE_STRING, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
        new (data_.data()) T(args...);
                           ^
./soralog/include/soralog/circular_buffer.hpp:161:21: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::Node::Node<std::__1::basic_string_view<char, std::__1::char_traits<char>>, soralog::Sink::ThreadInfoType, soralog::Level, FMT_COMPILE_STRING, unsigned long, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
        new (&node) Node(args...);
                    ^
./soralog/include/soralog/sink.hpp:88:31: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::put<std::__1::basic_string_view<char, std::__1::char_traits<char>>, soralog::Sink::ThreadInfoType, soralog::Level, FMT_COMPILE_STRING, unsigned long, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
          auto node = events_.put(name, thread_info_type_, level, format,
                              ^
./soralog/include/soralog/logger.hpp:44:16: note: in instantiation of function template specialization 'soralog::Sink::push<FMT_COMPILE_STRING, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
        sink_->push(name_, level, format, args...);
               ^
./soralog/include/soralog/logger.hpp:65:7: note: in instantiation of function template specialization 'soralog::Logger::push<FMT_COMPILE_STRING, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
      push(level, std::forward<Format>(format), args...);
      ^
./soralog/include/soralog/macro.hpp:30:12: note: in instantiation of function template specialization 'soralog::Logger::log<FMT_COMPILE_STRING, fmt::v8::join_view<boost::container::vec_iterator<std::__1::basic_string<char> *, false>, boost::container::vec_iterator<std::__1::basic_string<char> *, false>, char>>' requested here
      log->log(level, std::forward<Format>(fmt), std::move(args)()...);
           ^
cpp-libp2p/src/protocol_muxer/multiselect/multiselect_instance.cpp:347:7: note: in instantiation of function template specialization 'soralog::macro::proxy<soralog::Logger, FMT_COMPILE_STRING, (lambda at cpp-libp2p/src/protocol_muxer/multiselect/multiselect_instance.cpp:347:7)>' requested here
      SL_DEBUG(log(), "Failed to negotiate protocols: {}",
      ^
./soralog/include/soralog/macro.hpp:122:3: note: expanded from macro 'SL_DEBUG'
  _SL_LOG((LOG), soralog::Level::DEBUG, (FMT), ##__VA_ARGS__, Z)
  ^
./soralog/include/soralog/macro.hpp:75:19: note: expanded from macro '_SL_LOG'
  soralog::macro::proxy(            \
                  ^
1 error generated.

I actually managed to "fix" this one by going through the entire stack of functions on the failed call stack and replacing every const Args &...args with Args &&...args and then using std::forward<Args>(args)... instead of args... or (in the one place) std::move(args)... (check saurik@0e2abb9 to see what I did), but one function--in soralog::Sink::push--uses its arguments multiple times (which means that I would think I can't safely forward r-values through it, as they might end up getting used after they are moved).

soralog/include/soralog/sink.hpp

Lines 87 to 89 in 761f1e9

	while (true) {
	auto node = events_.put(name, thread_info_type_, level, format,
	max_message_length_, args...);

soralog/include/soralog/sink.hpp

Lines 108 to 109 in 761f1e9

	for (const auto &sink : underlying_sinks_) {
	sink->push(name, level, format, args...);

---

2. In fmtlib/fmt@f055ebb from Feb 4 2022, fmt made some "ostream operators opt in to reduce the risk of ODR violations", whcih is now causing a static_assert on "formattable" "Cannot format an argument. To make type T formattable provide a formatter specialization: https://fmt.dev/latest/api.html#udt" while trying to format an std::error_code. This is fixable if I #define FMT_DEPRECATED_OSTREAM, but I don't know if this needs to be done by cpp-libp2p or soralog.

https://github.com/libp2p/cpp-libp2p/blob/890b53dd73452a555a5c7feaa9f73c5bdca1a9af/src/protocol/identify/identify_msg_processor.cpp#L144-L145

      log_->error("cannot read an identify message from peer {}, {}: {}",
                  peer_id_str, peer_addr_str, msg_res.error());

In file included from cpp-libp2p/src/protocol/identify/identify_msg_processor.cpp:6:
In file included from ./cpp-libp2p/include/libp2p/protocol/identify/identify_msg_processor.hpp:16:
In file included from ./cpp-libp2p/include/libp2p/host/host.hpp:14:
In file included from ./cpp-libp2p/include/libp2p/event/bus.hpp:17:
In file included from ./cpp-libp2p/include/libp2p/log/logger.hpp:10:
In file included from ./soralog/include/soralog/logger.hpp:13:
In file included from ./soralog/include/soralog/sink.hpp:14:
In file included from ./soralog/include/soralog/event.hpp:14:
In file included from ./p2p/fmt/include/fmt/format.h:49:
./p2p/fmt/include/fmt/core.h:1711:3: error: static_assert failed due to requirement 'formattable' "Cannot format an argument. To make type T formattable provide a formatter<T> specialization: https://fmt.dev/latest/api.html#udt"
  static_assert(
  ^
./p2p/fmt/include/fmt/core.h:1837:23: note: in instantiation of function template specialization 'fmt::v8::detail::make_arg<true, fmt::v8::basic_format_context<fmt::v8::appender, char>, fmt::v8::detail::type::custom_type, const std::__1::error_code &, 0>' requested here
        data_{detail::make_arg<
                      ^
./p2p/fmt/include/fmt/core.h:1856:10: note: in instantiation of function template specialization 'fmt::v8::format_arg_store<fmt::v8::basic_format_context<fmt::v8::appender, char>, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>::format_arg_store<const std::__1::basic_string<char> &, const std::__1::basic_string<char> &, const std::__1::error_code &>' requested here
  return {std::forward<Args>(args)...};
         ^
./p2p/fmt/include/fmt/core.h:3189:41: note: in instantiation of function template specialization 'fmt::v8::make_format_args<fmt::v8::basic_format_context<fmt::v8::appender, char>, const std::__1::basic_string<char> &, const std::__1::basic_string<char> &, const std::__1::error_code &>' requested here
  return vformat_to_n(out, n, fmt, fmt::make_format_args(args...));
                                        ^
./soralog/include/soralog/event.hpp:62:18: note: in instantiation of function template specialization 'fmt::v8::format_to_n<char *, const std::__1::basic_string<char> &, const std::__1::basic_string<char> &, const std::__1::error_code &, 0>' requested here
            fmt::format_to_n(message_data_, max_message_length, format, args...)
                 ^
./soralog/include/soralog/circular_buffer.hpp:41:28: note: in instantiation of function template specialization 'soralog::Event::Event<soralog::Sink::ThreadInfoType, std::__1::basic_string_view<char, std::__1::char_traits<char>>, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
        new (data_.data()) T(args...);
                           ^
./soralog/include/soralog/circular_buffer.hpp:161:21: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::Node::Node<std::__1::basic_string_view<char, std::__1::char_traits<char>>, soralog::Sink::ThreadInfoType, soralog::Level, std::__1::basic_string_view<char, std::__1::char_traits<char>>, unsigned long, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
        new (&node) Node(args...);
                    ^
./soralog/include/soralog/sink.hpp:88:31: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::put<std::__1::basic_string_view<char, std::__1::char_traits<char>>, soralog::Sink::ThreadInfoType, soralog::Level, std::__1::basic_string_view<char, std::__1::char_traits<char>>, unsigned long, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
          auto node = events_.put(name, thread_info_type_, level, format,
                              ^
./soralog/include/soralog/logger.hpp:44:16: note: in instantiation of function template specialization 'soralog::Sink::push<std::__1::basic_string_view<char, std::__1::char_traits<char>>, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
        sink_->push(name_, level, format, args...);
               ^
./soralog/include/soralog/logger.hpp:153:7: note: in instantiation of function template specialization 'soralog::Logger::push<std::__1::basic_string_view<char, std::__1::char_traits<char>>, std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
      push(Level::ERROR, format, args...);
      ^
cpp-libp2p/src/protocol/identify/identify_msg_processor.cpp:144:13: note: in instantiation of function template specialization 'soralog::Logger::error<std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::error_code>' requested here
      log_->error("cannot read an identify message from peer {}, {}: {}",
            ^
1 error generated.

[saurik]

I am now running into another issue with newer versions of soralog (with libp2p). :/

In file included from cpp-libp2p/src/basic/scheduler/asio_scheduler_backend.cpp:8:
In file included from ./cpp-libp2p/include/libp2p/log/logger.hpp:10:
In file included from ./soralog/include/soralog/logger.hpp:13:
In file included from ./soralog/include/soralog/sink.hpp:14:
./soralog/include/soralog/event.hpp:62:65: error: call to consteval function 'fmt::basic_format_string<char, const std::basic_string<char> &>::basic_format_string<std::basic_string_view<char>, 0>' is not a constant expression
            fmt::format_to_n(message_data_, max_message_length, format, args...)
                                                                ^
./soralog/include/soralog/circular_buffer.hpp:41:28: note: in instantiation of function template specialization 'soralog::Event::Event<soralog::Sink::ThreadInfoType, std::basic_string_view<char>, std::basic_string<char>>' requested here
        new (data_.data()) T(args...);
                           ^
./soralog/include/soralog/circular_buffer.hpp:161:21: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::Node::Node<std::basic_string_view<char>, soralog::Sink::ThreadInfoType, soralog::Level, std::basic_string_view<char>, unsigned long, std::basic_string<char>>' requested here
        new (&node) Node(args...);
                    ^
./soralog/include/soralog/sink.hpp:88:31: note: in instantiation of function template specialization 'soralog::CircularBuffer<soralog::Event>::put<std::basic_string_view<char>, soralog::Sink::ThreadInfoType, soralog::Level, std::basic_string_view<char>, unsigned long, std::basic_string<char>>' requested here
          auto node = events_.put(name, thread_info_type_, level, format,
                              ^
./soralog/include/soralog/logger.hpp:44:16: note: in instantiation of function template specialization 'soralog::Sink::push<std::basic_string_view<char>, std::basic_string<char>>' requested here
        sink_->push(name_, level, format, args...);
               ^
./soralog/include/soralog/logger.hpp:170:7: note: in instantiation of function template specialization 'soralog::Logger::push<std::basic_string_view<char>, std::basic_string<char>>' requested here
      push(Level::CRITICAL, format, args...);
      ^
cpp-libp2p/src/basic/scheduler/asio_scheduler_backend.cpp:40:12: note: in instantiation of function template specialization 'soralog::Logger::critical<std::basic_string<char>>' requested here
      log->critical("cannot set timer: {}", ec.message());
           ^
./soralog/include/soralog/event.hpp:62:65: note: function parameter 'format' with unknown value cannot be used in a constant expression
            fmt::format_to_n(message_data_, max_message_length, format, args...)
                                                                ^
./soralog/include/soralog/event.hpp:46:25: note: declared here
          const Format &format, size_t max_message_length, const Args &...args)
                        ^
1 error generated.