Overriding global enum operators (e.g. via magic_enum) causes static initialization crash on macOS

[oxiKKK]

What version of protobuf and what language are you using?
Version: vcpkg/v5.29.5
Language: C++

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

macOS Sequoia 15.6.1

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

AppleClang 17.0.0.17000013

General Information

Custom-built .proto files into a C++ combination together with globally-overriden enum bitwise operators cause protobuf to crash during static initialization only on macOS. On other platforms such as Linux and Windows this is fine.

Steps to reproduce the behavior are shown in this minimal-working example:

https://github.com/oxiKKK/protobuf-magic_enum-repro

This is the magic_enum::bitwise_operators namespace:

https://github.com/Neargye/magic_enum/blob/83ab7f4f578bd00e1026a7cd9f7baa4f1a62cbeb/include/magic_enum/magic_enum.hpp#L1510

Code:

#include <iostream>
#include <magic_enum/magic_enum.hpp>

// >>>> THIS CAUSES CRASH <<<<
using namespace magic_enum::bitwise_operators;

// >>> NOW INCLUDE PROTOBUF <<<
#include "example.pb.h"
#include <google/protobuf/message.h>

int main() {
  std::cout << "Creating protobuf message..." << std::endl;

  example::Person person;
  person.set_name("John Doe");
  person.set_id(123);
  person.set_email("john.doe@example.com");

  std::cout << "Person created successfully!" << std::endl;
  std::cout << "Name: " << person.name() << std::endl;
  std::cout << "ID: " << person.id() << std::endl;
  std::cout << "Email: " << person.email() << std::endl;

  // Create an AddressBook with the person
  example::AddressBook address_book;
  auto *new_person = address_book.add_people();
  *new_person = person;

  std::cout << "AddressBook created with " << address_book.people_size()
            << " person(s)" << std::endl;

  return 0;
}

Results in a segfault:

> protobuf-magic_enum-repro % lldb ./build/magic_enum_protobuf_repro
(lldb) target create "./build/magic_enum_protobuf_repro"
Current executable set to '/Users/XX/dev/protobuf-magic_enum-repro/build/magic_enum_protobuf_repro' (arm64).
(lldb) r
Process 57912 launched: '/Users/XX/dev/protobuf-magic_enum-repro/build/magic_enum_protobuf_repro' (arm64)
Process 57912 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x53707937)
    frame #0: 0x0000000100002b44 magic_enum_protobuf_repro`std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::__is_long[abi:ne190102](this="") const at string:1881:29
   1878     if (__libcpp_is_constant_evaluated() && __builtin_constant_p(__r_.first().__l.__is_long_)) {
   1879       return __r_.first().__l.__is_long_;
   1880     }
-> 1881     return __r_.first().__s.__is_long_;
   1882   }
   1883
   1884   static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __begin_lifetime(pointer __begin, size_type __n) {
Target 0: (magic_enum_protobuf_repro) stopped.
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x53707937)
  * frame #0: 0x0000000100002b44 magic_enum_protobuf_repro`std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::__is_long[abi:ne190102](this="") const at string:1881:29
    frame #1: 0x0000000100002e80 magic_enum_protobuf_repro`std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::__get_pointer[abi:ne190102](this="") const at string:2009:12
    frame #2: 0x0000000100002574 magic_enum_protobuf_repro`std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::data[abi:ne190102](this="") const at string:1705:30
    frame #3: 0x00000001000063fc magic_enum_protobuf_repro`absl::lts_20250127::string_view::string_view<std::__1::allocator<char>>(this=0x000000016fdf8f78, str="") at string_view.h:193:25
    frame #4: 0x0000000100243e28 magic_enum_protobuf_repro`google::protobuf::internal::TcParser::FastSS1(google::protobuf::MessageLite*, char const*, google::protobuf::internal::ParseContext*, google::protobuf::internal::TcFieldData, google::protobuf::internal::TcParseTableBase const*, unsigned long long) [inlined] google::protobuf::internal::(anonymous namespace)::IsValidUTF8(field=0x000000016fdf9398) at generated_message_tctable_lite.cc:1402:42
    frame #5: 0x0000000100243e14 magic_enum_protobuf_repro`google::protobuf::internal::TcParser::FastSS1(google::protobuf::MessageLite*, char const*, google::protobuf::internal::ParseContext*, google::protobuf::internal::TcFieldData, google::protobuf::internal::TcParseTableBase const*, unsigned long long) [inlined] char const* google::protobuf::internal::TcParser::SingularString<unsigned char, google::protobuf::internal::ArenaStringPtr, (google::protobuf::internal::TcParser::Utf8Type)2>(msg=0x000000016fdf92e8, ptr="\U00000012\aexample\"1\n\U00000006Person\U00000012\f\n\U00000004name\U00000018\U00000001 \U00000001(\t\U00000012\n\n\U00000002id\U00000018\U00000002 \U00000001(\U00000005\U00000012\r\n\U00000005email\U00000018\U00000003 \U00000001(\t\".\n\vAddressBook\U00000012\U0000001f\n\U00000006people\U00000018\U00000001 \U00000003(\v2\U0000000f.example.Personb\U00000006proto3", ctx=0x000000016fdf90a8, data=TcFieldData @ 0x000000016fdf8e48, table=0x000000010047d0d0, hasbits=1) at generated_message_tctable_lite.cc:1435:11
    frame #6: 0x0000000100243c2c magic_enum_protobuf_repro`google::protobuf::internal::TcParser::FastSS1(msg=0x000000016fdf92e8, ptr="\n\rexample.proto\U00000012\aexample\"1\n\U00000006Person\U00000012\f\n\U00000004name\U00000018\U00000001 \U00000001(\t\U00000012\n\n\U00000002id\U00000018\U00000002 \U00000001(\U00000005\U00000012\r\n\U00000005email\U00000018\U00000003 \U00000001(\t\".\n\vAddressBook\U00000012\U0000001f\n\U00000006people\U00000018\U00000001 \U00000003(\v2\U0000000f.example.Personb\U00000006proto3", ctx=0x000000016fdf90a8, data=TcFieldData @ 0x000000016fdf8de8, table=0x000000010047d0d0, hasbits=0) at generated_message_tctable_lite.cc:1457:28
    frame #7: 0x00000001002ae318 magic_enum_protobuf_repro`bool google::protobuf::internal::MergeFromImpl<false>(absl::lts_20250127::string_view, google::protobuf::MessageLite*, google::protobuf::internal::TcParseTableBase const*, google::protobuf::MessageLite::ParseFlags) [inlined] google::protobuf::internal::TcParser::TagDispatch(msg=0x000000016fdf92e8, ptr="\n\rexample.proto\U00000012\aexample\"1\n\U00000006Person\U00000012\f\n\U00000004name\U00000018\U00000001 \U00000001(\t\U00000012\n\n\U00000002id\U00000018\U00000002 \U00000001(\U00000005\U00000012\r\n\U00000005email\U00000018\U00000003 \U00000001(\t\".\n\vAddressBook\U00000012\U0000001f\n\U00000006people\U00000018\U00000001 \U00000003(\v2\U0000000f.example.Personb\U00000006proto3", ctx=0x000000016fdf90a8, (null)=TcFieldData @ 0x000000016fdf90a0, table=0x000000010047d0d0, hasbits=0) at generated_message_tctable_impl.h:1105:28
    frame #8: 0x00000001002ae264 magic_enum_protobuf_repro`bool google::protobuf::internal::MergeFromImpl<false>(absl::lts_20250127::string_view, google::protobuf::MessageLite*, google::protobuf::internal::TcParseTableBase const*, google::protobuf::MessageLite::ParseFlags) [inlined] google::protobuf::internal::TcParser::ParseLoop(msg=0x000000016fdf92e8, ptr="\n\rexample.proto\U00000012\aexample\"1\n\U00000006Person\U00000012\f\n\U00000004name\U00000018\U00000001 \U00000001(\t\U00000012\n\n\U00000002id\U00000018\U00000002 \U00000001(\U00000005\U00000012\r\n\U00000005email\U00000018\U00000003 \U00000001(\t\".\n\vAddressBook\U00000012\U0000001f\n\U00000006people\U00000018\U00000001 \U00000003(\v2\U0000000f.example.Personb\U00000006proto3", ctx=0x000000016fdf90a8, table=0x000000010047d108) at generated_message_tctable_impl.h:1147:11
    frame #9: 0x00000001002ae1e8 magic_enum_protobuf_repro`bool google::protobuf::internal::MergeFromImpl<false>(input=(ptr_ = "\n\rexample.proto\U00000012\aexample\"1\n\U00000006Person\U00000012\f\n\U00000004name\U00000018\U00000001 \U00000001(\t\U00000012\n\n\U00000002id\U00000018\U00000002 \U00000001(\U00000005\U00000012\r\n\U00000005email\U00000018\U00000003 \U00000001(\t\".\n\vAddressBook\U00000012\U0000001f\n\U00000006people\U00000018\U00000001 \U00000003(\v2\U0000000f.example.Personb\U00000006proto3", length_ = 131), msg=0x000000016fdf92e8, tc_table=0x000000010047d0d0, parse_flags=kParse) at message_lite.cc:218:9
    frame #10: 0x00000001002b20c8 magic_enum_protobuf_repro`bool google::protobuf::MessageLite::ParseFrom<(google::protobuf::MessageLite::ParseFlags)1, absl::lts_20250127::string_view>(this=0x000000016fdf92e8, input=0x000000016fdf9218) at message_lite.h:1149:10
    frame #11: 0x00000001002b2370 magic_enum_protobuf_repro`google::protobuf::MessageLite::ParseFromArray(this=0x000000016fdf92e8, data=0x000000010044ddd0, size=131) at message_lite.cc:409:10
    frame #12: 0x0000000100144c8c magic_enum_protobuf_repro`google::protobuf::EncodedDescriptorDatabase::Add(this=0x0000000153707830, encoded_file_descriptor=0x000000010044ddd0, size=131) at descriptor_database.cc:547:12
    frame #13: 0x000000010001d504 magic_enum_protobuf_repro`google::protobuf::DescriptorPool::InternalAddGeneratedFile(encoded_file_descriptor=0x000000010044ddd0, size=131) at descriptor.cc:2248:3
    frame #14: 0x0000000100203fe8 magic_enum_protobuf_repro`google::protobuf::(anonymous namespace)::AddDescriptorsImpl(table=0x000000010047c058) at generated_message_reflection.cc:3712:3
    frame #15: 0x0000000100203f3c magic_enum_protobuf_repro`google::protobuf::internal::AddDescriptors(table=0x000000010047c058) at generated_message_reflection.cc:3727:3
    frame #16: 0x00000001000062d8 magic_enum_protobuf_repro`::__cxx_global_var_init() at example.pb.cc:685:10
    frame #17: 0x00000001000062ec magic_enum_protobuf_repro`_GLOBAL__I_000102 at example.pb.cc:0
    frame #18: 0x000000019b9daefc dyld`invocation function for block in dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 444
    frame #19: 0x000000019ba1789c dyld`invocation function for block in dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 324
    frame #20: 0x000000019ba375cc dyld`invocation function for block in mach_o::Header::forEachSection(void (mach_o::Header::SectionInfo const&, bool&) block_pointer) const + 240
    frame #21: 0x000000019ba34358 dyld`mach_o::Header::forEachLoadCommand(void (load_command const*, bool&) block_pointer) const + 208
    frame #22: 0x000000019ba35a98 dyld`mach_o::Header::forEachSection(void (mach_o::Header::SectionInfo const&, bool&) block_pointer) const + 124
    frame #23: 0x000000019ba1736c dyld`dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 516
    frame #24: 0x000000019b9dacb4 dyld`dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 176
    frame #25: 0x000000019b9e2670 dyld`dyld4::JustInTimeLoader::runInitializers(dyld4::RuntimeState&) const + 36
    frame #26: 0x000000019b9db460 dyld`dyld4::Loader::runInitializersBottomUp(dyld4::RuntimeState&, dyld3::Array<dyld4::Loader const*>&, dyld3::Array<dyld4::Loader const*>&) const + 308
    frame #27: 0x000000019b9dfbf0 dyld`dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const::$_0::operator()() const + 180
    frame #28: 0x000000019b9db77c dyld`dyld4::Loader::runInitializersBottomUpPlusUpwardLinks(dyld4::RuntimeState&) const + 716
    frame #29: 0x000000019b9fca20 dyld`dyld4::APIs::runAllInitializersForMain() + 392
    frame #30: 0x000000019b9bfe00 dyld`dyld4::prepare(dyld4::APIs&, mach_o::Header const*) + 3092
    frame #31: 0x000000019b9bf1d8 dyld`dyld4::start(dyld4::KernelArgs*, void*, void*)::$_0::operator()() const + 236
    frame #32: 0x000000019b9beb4c dyld`start + 6000
(lldb) 

[honglooker]

@sbenzaquen, mind taking a look?