std::system_error on calc example

[mattulbrich]

Hi! I tried to run calc.cc from the example directory. Unfortunately, I received an error message

     $ cd example/
     $ g++ -I .. -std=c++11 calc.cc
     $ ./a.out 2+3*4
     Terminate called after throwing an instance of 'std::system_error'
       what():  Unknown error -1
     Aborted (core dumped)

This is both with g++ and with clang++. Apparently this call to std::call_once is responsible
https://github.com/yhirose/cpp-peglib/blob/21934dd1ce/peglib.h#L1483

[yhirose]

@mattulbrich, thanks for the report.

I have tried 'g++ -I .. -std=c++11 calc.cc' and 'clang++ -I .. -std=c++11 calc.cc' on my MacBook. But both worked fine, gave me '14' as a result.

Which OS or environment are you working on?

Thank you!

[mattulbrich]

Thanks for looking into it!
I was running (x)Ubuntu 14.04 at the time, but have now updated to Ubuntu 16.04. I still receive the same problem

$ ./a.out 2+3*4
terminate called after throwing an instance of 'std::system_error'
  what():  Unknown error -1
Aborted (core dumped)
$ g++ --version
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609

Also on another (opensuse) machine with g++ (SUSE Linux) 4.8.3 20140627 [gcc-4_8-branch revision 212064] I get the same error message.

[mattulbrich]

And I can provide a stacktrace for you. Perhaps it helps a little ...

(gdb) bt
#0  0x00007ffff72400a7 in raise () from /lib64/libc.so.6
#1  0x00007ffff7241458 in abort () from /lib64/libc.so.6
#2  0x00007ffff7b32975 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6
#3  0x00007ffff7b309f6 in ?? () from /usr/lib64/libstdc++.so.6
#4  0x00007ffff7b30a41 in std::terminate() () from /usr/lib64/libstdc++.so.6
#5  0x00007ffff7b30c58 in __cxa_throw () from /usr/lib64/libstdc++.so.6
#6  0x00007ffff7b86dbf in std::__throw_system_error(int) () from /usr/lib64/libstdc++.so.6
#7  0x000000000041590a in std::call_once<peg::DefinitionReference::get_rule() const::{lambda()#1}>(std::once_flag&, peg::DefinitionReference::get_rule() const::{lambda()#1}&&) (__once=..., __f=<unknown type in /amd.home/home/i57/mulbrich/tmp/cpp-peglib-master/example/a.out, CU 0x15b, DIE 0x5f779>)
    at /usr/include/c++/4.8/mutex:794
#8  0x0000000000408684 in peg::DefinitionReference::get_rule (this=0x66fba8) at ../peglib.h:1485
#9  0x0000000000409df0 in peg::ParserGenerator::DetectLeftRecursion::visit (this=0x7fffffffd8d0, ope=...) at ../peglib.h:1744
#10 0x0000000000408a00 in peg::DefinitionReference::accept (this=0x66fba8, v=...) at ../peglib.h:1507

[yhirose]

I installed Ubuntu 16.04 on VirtualBox on my MacBook. I am now able to reproduce the problem.

I googled and found some helpful information:
http://stackoverflow.com/questions/15311469/throwing-an-exception-from-stdcall-once
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60662
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58929

According to the suggestion on the above, I tried the following and it worked!

g++ -I .. -std=c++11 calc.cc -pthread

Could you please try it again with -pthread?

[mattulbrich]

It works!

The resulting executable now links against libpthread.so.0.
Astonishingly, no linker error was produced due to a missing function pointer in __gthread_once, this seems to be deferred to runtime.

Thank you very much for finding this out!

[yhirose]

Thanks for the good report!

[aixi]

very helpful, I encounter a bug in protobuf::Message::DebugString(), this function will call std::call_once and throw std::system_error